SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
Jun. 30, 2025
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Accounting policies are consistent for each operating segment.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, the Company evaluates its estimates and assumptions, including those related to revenue recognition, allowance for credit losses, the useful lives and recoverability of long-lived and intangible assets, goodwill impairment assessment, income taxes, accounting for business combinations, stock-based compensation, estimating the Company's incremental borrowing rate for its leases, the estimate of net realizable value of inventory, the determination of stand-alone selling prices of various performance obligations, and contingencies, among others. The Company bases these estimates on historical and anticipated results, trends, and various other assumptions that it believes are reasonable, including assumptions as to future events. These estimates form the basis for making judgments about the carrying values of assets and liabilities and recorded revenues and expenses. Actual results could differ from these estimates.
Revenue Recognition	Revenue Recognition The Company derives revenues primarily by (i) providing access to its proprietary database of commercial real estate information, including benchmarking and analytics for the hospitality industry and analytics for lenders, and (ii) providing online marketplaces for professional property management companies, property owners, real estate agents and brokers, and landlords, in each case, typically through a fixed monthly fee for its subscription-based advertising services. Other subscription- based services include (i) real estate and lease management solutions to commercial customers and real estate investors, (ii) access to applications to manage workflow for residential real estate agents, and (iii) access to its AI-powered spatial data platform to create high-fidelity and high-accuracy digital twins of physical spaces to generate valuable data, analytics, and insights for customers. Subscription contract rates are generally based on the number of sites, number of users, organization size, the customer’s business focus, geography, the number of properties reported on or analyzed, the number and types of services to which a customer subscribes, the number of properties a customer advertises, the number of digital twins hosted, the number of transactions and average transaction size a broker or agent has closed, and the prominence and placement of a customer's advertised properties in the search results. The Company’s subscription-based license, advertising packages, and membership agreements generally renew automatically, and a majority have a term of at least one year. Revenues from subscription-based contracts were approximately 95% and 96% of total revenues for the three months ended June 30, 2025 and 2024, respectively, and approximately 96% and 96% of total revenues for the six months ended June 30, 2025 and 2024, respectively. The Company also derives revenues from transaction-based services including: (i) an online auction platform for commercial real estate through Ten-X, (ii) the sale of Matterport cameras and capture equipment, (iii) providing assistance with the data capture process to create digital twins through Matterport, (iv) providing online tenant applications, including background and credit checks, and rental payment processing, and (v) ancillary products and services that are sold on an ad hoc basis. The Company analyzes contracts to determine the appropriate revenue recognition using the following steps: (i) identification of contracts with customers, (ii) identification of distinct performance obligations in the contract, (iii) determination of contract transaction price, (iv) allocation of contract transaction price to the performance obligations, and (v) determination of revenue recognition based on timing of satisfaction of the performance obligations. The Company recognizes revenues upon the satisfaction of its performance obligation(s) (upon transfer of control of promised services to its customers) in an amount that reflects the consideration to which it expects to be entitled to in exchange for those services. Revenues from subscription-based services are recognized on a straight-line basis over the term of the agreement. Revenues from transaction-based services are recognized when the promised product or services are delivered, which, in the case of Ten-X auctions, is at the time of a successful closing for the sale of a property. Revenues from product sales are recognized upon control transferring to the customers, which is generally upon shipment. Revenue for sales of Matterport cameras are recorded net of estimates of returns, as buyers are entitled to return the camera within 30 days from the date of purchase for a full refund. These rights are accounted for as variable consideration and recognized as a reduction to the revenue recognized. In limited circumstances, the Company's contracts with customers include promises to transfer multiple services, such as contracts for its subscription-based services and professional services or product sales, digital twin capture services, and subscription-based hosting service. For these contracts, the Company accounts for individual performance obligations separately if they are distinct, which involves the determination of the standalone selling price for each distinct performance obligation. Deferred revenue results from amounts billed in advance to customers or cash received from customers in advance of the Company's fulfillment of its performance obligation(s) and is recognized as those obligations are satisfied. Contract assets represent a conditional right to consideration for satisfied performance obligations that become a receivable when the conditions are satisfied. Contract assets are generated when contractual billing schedules differ from revenue recognition timing. Certain sales commissions are considered incremental and recoverable costs of obtaining a contract with a customer. Sales commissions incurred for obtaining new contracts are deferred and then amortized as selling and marketing expenses (excluding customer base amortization) over the period of benefit that the Company has determined to be two years for our residential products and three years for all other products. The amortization periods were determined based on several factors, including the nature of the technology and proprietary data underlying the services being purchased, customer contract renewal rates and industry competition. Sales commissions that do not represent incremental costs of obtaining a contract, or that would otherwise be amortized over a period of one year or less, are not subject to capitalization.
Cost of Revenues	Cost of Revenues Cost of revenues principally consists of salaries, benefits, bonuses, stock-based compensation expenses, and other indirect costs for the Company's researchers who collect and analyze the real estate data that is the basis for the Company's information, analytic, and online marketplace services and for employees that support these products. Additionally, cost of revenues includes amortization of acquired trade names, technology, and certain other intangible assets; product hosting costs; credit card and other transaction fees relating to processing customer transactions; cost of data from third-party data sources; costs of capture services; costs of Matterport cameras sold; and costs related to advertising purchased on behalf of customers
Foreign Currency Translation	Foreign Currency Translation The Company’s reporting currency is the U.S. dollar. The functional currency for the majority of its operations is the local currency, with the exception of certain international locations for which the functional currency is the British Pound or U.S. dollar. Assets and liabilities denominated in a foreign currency are translated into U.S. dollars using the exchange rates in effect as of the balance sheet date. Gains and losses resulting from translation are included in accumulated other comprehensive loss. Currency gains and losses on the translation of intercompany loans made to foreign subsidiaries that are of a long-term investment nature are also included in accumulated other comprehensive loss. Gains and losses resulting from transactions denominated in a currency other than the functional currency of the entity are included in other income (expense), net in the condensed consolidated statements of operations using the average exchange rates in effect during the period.
Income Taxes	Income Taxes Deferred income taxes result from temporary differences between the tax basis of assets and liabilities and the basis reported in the Company’s condensed consolidated financial statements. Deferred tax liabilities and assets are determined based on the difference between the financial statement and the tax basis of assets and liabilities using enacted rates in effect during the year in which the Company expects differences to reverse. Valuation allowances are provided against assets, including net operating losses, if the Company determines it is more likely than not that some portion or all of an asset may not be realized. Interest and penalties related to income tax matters are recognized in income tax expense. The Company has elected to record the GILTI under the current-period cost method. On July 4, 2025, the OBBBA was signed into law in the U.S. which contains a broad range of tax reform provisions affecting businesses. We are currently evaluating the impact of the OBBBA and expect the results of such evaluation to be reflected in our third quarter Form 10-Q.
Net Income (Loss) Per Share	Net Income (Loss) Per Share Net income (loss) per share is computed by dividing net income (loss) by the weighted-average number of common shares outstanding during the period on a basic and diluted basis. The Company’s potentially dilutive securities include outstanding stock options and unvested stock-based awards, which include restricted stock awards that vest over a specific service period, restricted stock awards with a performance condition, restricted stock awards with a performance condition and a market condition, restricted stock units, and Matching RSUs awarded under the MSPP. Shares underlying unvested restricted stock awards that vest based on a performance condition and those that vest based on a performance and market condition that have not been achieved as of the end of the period are not included in the computation of basic or diluted earnings per share. Diluted net income (loss) per share considers the impact of potentially dilutive securities except when the inclusion of the potentially dilutive securities would have an anti-dilutive effect.
Stock-Based Compensation and Stock Incentive Plans	Stock-Based Compensation Equity instruments issued in exchange for services performed by officers, employees, and directors of the Company are accounted for using a fair value-based method and the fair value of such equity instruments is recognized as expense in the condensed consolidated statements of operations. For stock-based awards that vest over a specific service period, compensation expense is measured based on the fair value of the awards at the grant date and is recognized on a straight-line basis over the service period of the awards, net of an estimated forfeiture rate. For equity instruments that vest based on achievement of a performance condition or both a performance and market condition, stock-based compensation expense is recognized over the service period of the awards based on the expected achievement of the related performance conditions at the end of each reporting period. If the Company's initial estimates of the achievement of the performance conditions change, the related stock-based compensation expense may fluctuate from period to period based on those estimates. If the performance conditions are not met, no stock-based compensation expense will be recognized and any previously recognized stock-based compensation expense will be reversed. For awards with both a performance and a market condition, the Company estimates the fair value of each equity instrument granted on the date of grant using a Monte-Carlo simulation model. This pricing model uses multiple simulations to evaluate the probability of achieving the market condition to calculate the fair value of the awards, which includes the recent market price and volatility of the Company's shares. When determining the grant date fair value of all stock-based awards, the Company considers whether it is in possession of any material, non-public information that upon its release would have a material effect on its share price, and if so, whether the observable share price or expected volatility assumptions used in determining the fair value of the awards should be adjusted. The Company estimates the fair value of its performance-based restricted stock awards with market conditions on the date of grant using a Monte-Carlo simulation valuation model. This pricing model uses multiple simulations to evaluate the probability of achieving the market condition to calculate the fair value of the awards. Expense is only recorded for awards that are expected to vest, net of estimated forfeitures.
Loss Contingencies and Litigation Expense	Loss Contingencies and Litigation Expense The Company is subject to the possibility of losses from various contingencies, including certain legal proceedings. Significant judgment is necessary to estimate the probability and amount of a loss, if any, from such contingencies. An accrual is made when it is probable that a liability has been incurred or an asset has been impaired, and the amount of loss can be reasonably estimated. In accounting for the resolution of contingencies, significant judgment may be necessary to estimate amounts pertaining to periods prior to the resolution that are charged to operations in the period of resolution and amounts related to future periods. If only a range of estimated losses can be determined, the Company records an amount within the range that, in its judgment, reflects the most likely outcome; if none of the estimates within that range are a better estimate than any other amount, the Company records the low end of the range. Any such accrual would be charged to expense in the appropriate period.
Cash, Cash Equivalents, and Restricted Cash	Cash, Cash Equivalents, and Restricted Cash The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. Restricted cash consists of cash deposited as collateral related to a litigation bond in a third-party insured account.
Allowance for Credit Losses	Allowance for Credit Losses The Company maintains an allowance for credit losses to cover its current expected credit losses on its trade receivables and contract assets arising from the failure of customers to make contractual payments. The Company estimates credit losses expected over the life of its trade receivables and contract assets based on historical information combined with current conditions that may affect a customer’s ability to pay and reasonable and supportable forecasts. While the Company uses various credit quality metrics, it primarily monitors collectability by reviewing the duration of collection pursuits on its delinquent trade receivables and historical write-off trends. Based on the Company’s experience, the customer's delinquency status, which is analyzed periodically, is the strongest indicator of the credit quality of the underlying trade receivables. The Company’s policy is to write off trade receivables when they are deemed uncollectible. Under the CECL impairment model, the Company develops and documents its allowance for credit losses on its trade receivables based on five portfolio segments. The determination of portfolio segments is based primarily on the qualitative consideration of the nature of the Company’s business operations and the characteristics of the underlying trade receivables, as follows: •CoStar Portfolio Segment - The CoStar portfolio segment consists of two classes of trade receivables based on geographical location: North America and International. •Information Services Portfolio Segment - The Information Services portfolio segment consists of four classes of trade receivables: CoStar Real Estate Manager; Hospitality, North America; Hospitality, International, and other Information Services. •Multifamily Portfolio Segment - The Multifamily portfolio segment consists of one class of trade receivables. •LoopNet Portfolio Segment - The LoopNet portfolio segment consists of one class of trade receivables. •Other Revenues Portfolio Segment - The Other Revenues portfolio segment consists of two classes of trade receivables: Matterport and other marketplaces. The majority of Residential revenue is e-commerce based and does not result in accounts receivable. Residential accounts receivable and the related allowance for credit losses are not material.
Inventories	Inventories Inventories consist primarily of finished goods, assemblies, and raw materials. Assemblies are generally purchased from contract manufacturers. Inventories are valued at the lower of cost or net realizable value. Costs are determined using standard cost, which approximates actual cost on a first-in, first-out basis. The Company assesses the valuation of inventory and periodically adjusts the value for estimated excess and obsolete inventory based upon estimates of future demand and market conditions, as well as damaged or otherwise impaired goods. Inventories are included in prepaid expenses and other current assets on the Company's condensed consolidated balance sheets.
Leases	Leases The determination of whether an arrangement contains a lease and the classification of a lease, if applicable, is made at the commencement of the arrangement, at which time the Company also measures and recognizes a ROU asset, representing the Company’s right to use the underlying asset, and a lease liability, representing the Company’s obligation to make lease payments under the terms of the arrangement. For the purposes of recognizing ROU assets and lease liabilities associated with the Company’s leases, the Company has elected the practical expedient to not recognize a ROU asset or lease liability for short-term leases, which are leases with a term of 12 months or less. The lease term is defined as the noncancellable portion of the lease term, plus any periods covered by an option to extend the lease if it is reasonably certain that the option will be exercised. In determining the amount of lease payments used in measuring ROU assets and lease liabilities, the Company has elected the practical expedient not to separate non-lease components from lease components for all classes of underlying assets. Consideration deemed part of the lease payments used to measure ROU assets and lease liabilities generally includes fixed payments and variable payments based on either an index or a rate, offset by lease incentives. Upon commencement, the initial ROU asset also includes any lease prepayments. ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. The rates implicit within the Company's leases are generally not determinable. Therefore, the Company's incremental borrowing rate is used to determine the present value of lease payments. The determination of the Company’s incremental borrowing rate requires judgment and is determined at lease commencement and is subsequently reassessed upon a modification to the lease arrangement. Lease costs related to the Company's operating leases are generally recognized as a single ratable lease cost over the lease term.
Equity Investment	Equity Investment The Company holds an investment in publicly held equity securities in which the Company does not have a controlling interest or exercise significant influence. The equity securities are included in the Equity investment caption on the condensed consolidated balance sheets and are measured at fair value with changes recorded through other income (expense), net on the condensed consolidated statements of operations.
Long-Lived Assets, Intangible Assets and Goodwill	Long-Lived Assets, Intangible Assets, and Goodwill Long-lived assets, such as property and equipment and purchased intangibles subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The Company capitalizes interest on borrowings during the active construction period of major capital projects. Capitalized interest is added to the cost of the underlying asset and amortized over the estimated useful life of the asset. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to the estimated undiscounted future cash flows expected to be generated by the asset or asset group. If the carrying amount of an asset exceeds its estimated undiscounted future cash flows, an impairment charge is recognized in the amount by which the carrying amount of the asset exceeds the fair value of the asset. Goodwill is tested for impairment at least annually, on October 1, or more frequently if an event or other circumstance indicates that the fair value of a reporting unit may be below its carrying amount. The Company may first assess qualitative factors to evaluate whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, or elect to bypass the qualitative assessment. If it is determined that it is more likely than not that the fair value of a reporting unit is less than its carrying value, or the Company elects to bypass the qualitative assessment, the Company then performs a quantitative assessment by determining the fair value of each reporting unit. The estimate of the fair value of each reporting unit is based on a projected discounted cash flow model that includes significant assumptions and estimates, including the discount rate, growth rate, and future financial performance. Assumptions about the discount rate are based on a weighted-average cost of capital for comparable companies. Assumptions about the growth rate and future financial performance of a reporting unit are based on the Company’s forecasts, business plans, economic projections, and anticipated future cash flows. The fair value of each reporting unit is compared to the carrying amount of the reporting unit. If the carrying value of the reporting unit exceeds the fair value, then an impairment loss is recognized for the difference.
Long-Lived Assets, Intangible Assets and Goodwill	Long-Lived Assets, Intangible Assets, and Goodwill Long-lived assets, such as property and equipment and purchased intangibles subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The Company capitalizes interest on borrowings during the active construction period of major capital projects. Capitalized interest is added to the cost of the underlying asset and amortized over the estimated useful life of the asset. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to the estimated undiscounted future cash flows expected to be generated by the asset or asset group. If the carrying amount of an asset exceeds its estimated undiscounted future cash flows, an impairment charge is recognized in the amount by which the carrying amount of the asset exceeds the fair value of the asset. Goodwill is tested for impairment at least annually, on October 1, or more frequently if an event or other circumstance indicates that the fair value of a reporting unit may be below its carrying amount. The Company may first assess qualitative factors to evaluate whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, or elect to bypass the qualitative assessment. If it is determined that it is more likely than not that the fair value of a reporting unit is less than its carrying value, or the Company elects to bypass the qualitative assessment, the Company then performs a quantitative assessment by determining the fair value of each reporting unit. The estimate of the fair value of each reporting unit is based on a projected discounted cash flow model that includes significant assumptions and estimates, including the discount rate, growth rate, and future financial performance. Assumptions about the discount rate are based on a weighted-average cost of capital for comparable companies. Assumptions about the growth rate and future financial performance of a reporting unit are based on the Company’s forecasts, business plans, economic projections, and anticipated future cash flows. The fair value of each reporting unit is compared to the carrying amount of the reporting unit. If the carrying value of the reporting unit exceeds the fair value, then an impairment loss is recognized for the difference.
Leasing Operations and Other Income (Expense), Net	Leasing Operations and Other Income (Expense), Net In February 2024, the Company closed on the purchase of an office tower and the land on which it rests in Arlington, Virginia. In January 2025, the Company relocated its headquarters from Washington, D.C. to Arlington, VA, initially occupying approximately 30% of the building. The Company intends to build out further space in this building to support anticipated growth and expansion of its operations in the coming years. Maintenance, physical facilities, leasing, property management, and other key responsibilities related to property ownership are outsourced to professional real-estate managers. The office tower measures approximately 550,000 rentable square feet. The Company accounted for the purchase of this building as an asset acquisition at the cost to acquire, including transaction costs. The Company estimated the fair values of acquired tangible assets (consisting of land, buildings, improvements, and other assets), identified intangible assets and liabilities (consisting of in-place leases and above- and below-market leases), and other liabilities based on its evaluation of information and estimates available at the date of acquisition. Based on these estimates, the Company allocated the total cost to the identified assets acquired and liabilities assumed based on their relative fair value. The fair value of the building and building improvements consists of the physical structure containing rentable area, as well as amenities such as parking structures, and was valued as if vacant, using the cost approach, which uses replacement cost data obtained from industry recognized guides less depreciation as an input to estimate the fair value, with consideration given to its age, functionality, use classification, construction quality, replacement cost, and accumulated depreciation (effective age vs. economic life). The Company also considered the value of the building using an income approach. The income approach uses market leasing assumptions to estimate the fair value of the property as if vacant, assuming lease-up at prevailing market rental rates over a market-based lease-up period, including deductions for lost-rent during lease-up and leasing costs. The cost and income approaches are reconciled to arrive at an estimated building fair value. The Company assessed the fair value of land based on market comparisons. The fair values of identified intangible assets and liabilities were determined based on the following: •The value allocable to the above- or below-market component of an acquired in-place lease is determined based upon the present value (using a discount rate that reflects the risks associated with the acquired lease) of the difference between: (i) the contractual amounts to be received pursuant to the lease over its remaining term and (ii) management's estimate of the amounts that would be received using market rates current at the time of the acquisition for the remaining term of the lease. Amounts allocated to above-market leases are recorded as above-market leases in intangible assets, net in the condensed consolidated balance sheets. These intangible assets are amortized on a straight-line basis as a component of leasing operations to other income (expense), net in the condensed consolidated statements of operations over the remaining terms of the respective leases. •Factors considered in determining the value allocable to in-place leases during hypothetical lease-up periods related to space that is leased at the time of acquisition include: (i) lost rent and operating cost recoveries during the hypothetical lease-up period and (ii) theoretical leasing commissions required to execute similar leases. These intangible assets are recorded as in-place leases in intangible assets, net in the condensed consolidated balance sheets and are amortized to other income (expense), net in the condensed consolidated statements of operations over the remaining terms of the existing leases.
Debt Issuance Costs	Debt Issuance Costs Costs incurred in connection with the issuance of long-term debt are deferred and amortized as interest expense over the term of the related debt using the effective interest method for term debt and on a straight-line basis for revolving debt. The Company made a policy election to classify deferred issuance costs on the revolving credit facility as a long-term asset on its condensed consolidated balance sheets. Upon a refinancing or amendment, previously capitalized debt issuance costs are expensed and included in loss on extinguishment of debt if the Company determines that there has been a substantial modification of the related debt. If the Company determines that there has not been a substantial modification of the related debt, any previously capitalized debt issuance costs are amortized as interest expense over the term of the new debt instrument.
Business Combinations	Business Combinations The Company includes the results of operations of the businesses that it acquires from the date of acquisition. The Company generally allocates the purchase consideration to the tangible assets acquired and liabilities assumed and intangible assets acquired based on their estimated fair values on the date of the acquisition. The purchase price is generally determined based on the fair value of the assets transferred, liabilities assumed, and equity interests issued, after considering any transactions that are separate from the business combination. The excess of the fair value of purchase consideration over the fair values of these identifiable assets and liabilities is recorded as goodwill. The Company applies significant assumptions, estimates, and judgments in determining the fair value of assets acquired and liabilities assumed on the acquisition date, especially with respect to intangible assets and contingent liabilities. Significant estimates in valuing certain intangible assets include, but are not limited to, future expected cash flows from acquired customer bases, acquired technology, acquired trade names, useful lives, royalty rates, and discount rates. Estimates of fair value are based on assumptions believed to be reasonable, but which are inherently uncertain and unpredictable and, as a result, actual results may differ from estimates. Any adjustments to provisional amounts that are identified during the measurement period, not to exceed one year from the date of acquisition, are recorded in the reporting period in which the adjustment amounts are determined. Upon the conclusion of the measurement period, any subsequent adjustments are recorded to earnings. The Company has elected the practical expedient provided under ASC 805, Business Combinations, which allows for contract assets and liabilities acquired or assumed in an acquisition to be measured in accordance with the accounting framework for revenue from contracts with customers as if the Company had originated the acquired contract. This is an exception to the general requirement to measure assets acquired and liabilities assumed at their fair value on the acquisition date. For a given acquisition, the Company may identify certain pre-acquisition contingencies as of the acquisition date and may extend its review and evaluation of these pre-acquisition contingencies throughout the measurement period in order to obtain sufficient information to assess whether the Company includes these contingencies as part of the fair value estimates of assets acquired and liabilities assumed and, if so, to determine their estimated amounts. If the Company cannot reasonably determine the fair value of a pre-acquisition contingency (non-income tax-related) by the end of the measurement period, which is generally the case given the nature of such matters, the Company will recognize an asset or a liability for such pre-acquisition contingency if: (i) it is probable that an asset existed or a liability had been assumed at the acquisition date and (ii) the amount of the asset or liability can be reasonably estimated. Subsequent to the measurement period, changes in the Company's estimates of such contingencies will affect earnings and could have a material effect on its results of operations and financial position. In addition, uncertain tax positions and tax-related valuation allowances assumed in connection with a business combination are initially estimated as of the acquisition date. The Company reevaluates these items based upon facts and circumstances that existed as of the acquisition date with any adjustments to its preliminary estimates being recorded to goodwill, provided that the Company is within the measurement period. Subsequent to the measurement period, changes to these uncertain tax positions and tax-related valuation allowances will affect the Company's provision for income taxes in its condensed consolidated statements of operations and comprehensive income and could have a material impact on its results of operations and financial position. Transaction costs associated with business combinations are expensed as incurred and are included in general and administrative expenses in the condensed consolidated statements of operations.
Recent Accounting Pronouncements and Not Yet Adopted	Recent Accounting Pronouncements Recent Accounting Pronouncements Not Yet Adopted In December 2023, the FASB issued ASU No. 2023-09 (Topic 740), Improvements to Income Tax Disclosures (Topic 740). The ASU requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as an expansion of other income tax disclosures. The ASU is effective on a prospective basis for annual reporting periods beginning after December 15, 2024. The Company is currently evaluating the impact this ASU will have on its consolidated financial statements and related disclosures. In November 2024, the FASB issued ASU No. 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40). The ASU requires incremental disclosures about specific expense categories, including but not limited to, purchases of inventory, employee compensation, depreciation, amortization, and selling expenses. The amendments are effective for fiscal years beginning after December 15, 2026 and for interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted and the amendments may be applied either prospectively or retrospectively. Management is currently evaluating this ASU to determine its impact on the Company's disclosures.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

6 Months Ended

Jun. 30, 2025

The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Accounting policies are consistent for each operating segment.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, the Company evaluates its estimates and assumptions, including those related to revenue recognition, allowance for credit losses, the useful lives and recoverability of long-lived and intangible assets, goodwill impairment assessment, income taxes, accounting for business combinations, stock-based compensation, estimating the Company's incremental borrowing rate for its leases, the estimate of net realizable value of inventory, the determination of stand-alone selling prices of various performance obligations, and contingencies, among others. The Company bases these estimates on historical and anticipated results, trends, and various other assumptions that it believes are reasonable, including assumptions as to future events. These estimates form the basis for making judgments about the carrying values of assets and liabilities and recorded revenues and expenses. Actual results could differ from these estimates.

Revenue Recognition

The Company derives revenues primarily by (i) providing access to its proprietary database of commercial real estate information, including benchmarking and analytics for the hospitality industry and analytics for lenders, and (ii) providing online marketplaces for professional property management companies, property owners, real estate agents and brokers, and landlords, in each case, typically through a fixed monthly fee for its subscription-based advertising services. Other subscription-

based services include (i) real estate and lease management solutions to commercial customers and real estate investors, (ii) access to applications to manage workflow for residential real estate agents, and (iii) access to its AI-powered spatial data platform to create high-fidelity and high-accuracy digital twins of physical spaces to generate valuable data, analytics, and insights for customers.

Subscription contract rates are generally based on the number of sites, number of users, organization size, the customer’s business focus, geography, the number of properties reported on or analyzed, the number and types of services to which a customer subscribes, the number of properties a customer advertises, the number of digital twins hosted, the number of transactions and average transaction size a broker or agent has closed, and the prominence and placement of a customer's advertised properties in the search results. The Company’s subscription-based license, advertising packages, and membership agreements generally renew automatically, and a majority have a term of at least one year. Revenues from subscription-based contracts were approximately 95% and 96% of total revenues for the three months ended June 30, 2025 and 2024, respectively, and approximately 96% and 96% of total revenues for the six months ended June 30, 2025 and 2024, respectively.

The Company also derives revenues from transaction-based services including: (i) an online auction platform for commercial real estate through Ten-X, (ii) the sale of Matterport cameras and capture equipment, (iii) providing assistance with the data capture process to create digital twins through Matterport, (iv) providing online tenant applications, including background and credit checks, and rental payment processing, and (v) ancillary products and services that are sold on an ad hoc basis.

The Company analyzes contracts to determine the appropriate revenue recognition using the following steps: (i) identification of contracts with customers, (ii) identification of distinct performance obligations in the contract, (iii) determination of contract transaction price, (iv) allocation of contract transaction price to the performance obligations, and (v) determination of revenue recognition based on timing of satisfaction of the performance obligations.

The Company recognizes revenues upon the satisfaction of its performance obligation(s) (upon transfer of control of promised services to its customers) in an amount that reflects the consideration to which it expects to be entitled to in exchange for those services. Revenues from subscription-based services are recognized on a straight-line basis over the term of the agreement. Revenues from transaction-based services are recognized when the promised product or services are delivered, which, in the case of Ten-X auctions, is at the time of a successful closing for the sale of a property. Revenues from product sales are recognized upon control transferring to the customers, which is generally upon shipment. Revenue for sales of Matterport cameras are recorded net of estimates of returns, as buyers are entitled to return the camera within 30 days from the date of purchase for a full refund. These rights are accounted for as variable consideration and recognized as a reduction to the revenue recognized.

In limited circumstances, the Company's contracts with customers include promises to transfer multiple services, such as contracts for its subscription-based services and professional services or product sales, digital twin capture services, and subscription-based hosting service. For these contracts, the Company accounts for individual performance obligations separately if they are distinct, which involves the determination of the standalone selling price for each distinct performance obligation.

Deferred revenue results from amounts billed in advance to customers or cash received from customers in advance of the Company's fulfillment of its performance obligation(s) and is recognized as those obligations are satisfied.

Contract assets represent a conditional right to consideration for satisfied performance obligations that become a receivable when the conditions are satisfied. Contract assets are generated when contractual billing schedules differ from revenue recognition timing.

Certain sales commissions are considered incremental and recoverable costs of obtaining a contract with a customer. Sales commissions incurred for obtaining new contracts are deferred and then amortized as selling and marketing expenses (excluding customer base amortization) over the period of benefit that the Company has determined to be two years for our residential products and three years for all other products. The amortization periods were determined based on several factors, including the nature of the technology and proprietary data underlying the services being purchased, customer contract renewal rates and industry competition. Sales commissions that do not represent incremental costs of obtaining a contract, or that would otherwise be amortized over a period of one year or less, are not subject to capitalization.

Cost of Revenues

Cost of revenues principally consists of salaries, benefits, bonuses, stock-based compensation expenses, and other indirect costs for the Company's researchers who collect and analyze the real estate data that is the basis for the Company's information, analytic, and online marketplace services and for employees that support these products. Additionally, cost of revenues includes amortization of acquired trade names, technology, and certain other intangible assets; product hosting costs; credit card and other transaction fees relating to processing customer transactions; cost of data from third-party data sources; costs of capture services; costs of Matterport cameras sold; and costs related to advertising purchased on behalf of customers

Foreign Currency Translation

The Company’s reporting currency is the U.S. dollar. The functional currency for the majority of its operations is the local currency, with the exception of certain international locations for which the functional currency is the British Pound or U.S. dollar. Assets and liabilities denominated in a foreign currency are translated into U.S. dollars using the exchange rates in effect as of the balance sheet date. Gains and losses resulting from translation are included in accumulated other comprehensive loss. Currency gains and losses on the translation of intercompany loans made to foreign subsidiaries that are of a long-term investment nature are also included in accumulated other comprehensive loss. Gains and losses resulting from transactions denominated in a currency other than the functional currency of the entity are included in other income (expense), net in the condensed consolidated statements of operations using the average exchange rates in effect during the period.

Income Taxes

Deferred income taxes result from temporary differences between the tax basis of assets and liabilities and the basis reported in the Company’s condensed consolidated financial statements. Deferred tax liabilities and assets are determined based on the difference between the financial statement and the tax basis of assets and liabilities using enacted rates in effect during the year in which the Company expects differences to reverse. Valuation allowances are provided against assets, including net operating losses, if the Company determines it is more likely than not that some portion or all of an asset may not be realized. Interest and penalties related to income tax matters are recognized in income tax expense.

The Company has elected to record the GILTI under the current-period cost method.

On July 4, 2025, the OBBBA was signed into law in the U.S. which contains a broad range of tax reform provisions affecting businesses. We are currently evaluating the impact of the OBBBA and expect the results of such evaluation to be reflected in our third quarter Form 10-Q.

Net Income (Loss) Per Share

Net income (loss) per share is computed by dividing net income (loss) by the weighted-average number of common shares outstanding during the period on a basic and diluted basis.

The Company’s potentially dilutive securities include outstanding stock options and unvested stock-based awards, which include restricted stock awards that vest over a specific service period, restricted stock awards with a performance condition, restricted stock awards with a performance condition and a market condition, restricted stock units, and Matching RSUs awarded under the MSPP. Shares underlying unvested restricted stock awards that vest based on a performance condition and those that vest based on a performance and market condition that have not been achieved as of the end of the period are not included in the computation of basic or diluted earnings per share. Diluted net income (loss) per share considers the impact of potentially dilutive securities except when the inclusion of the potentially dilutive securities would have an anti-dilutive effect.

Stock-Based Compensation and Stock Incentive Plans

Stock-Based Compensation

Equity instruments issued in exchange for services performed by officers, employees, and directors of the Company are accounted for using a fair value-based method and the fair value of such equity instruments is recognized as expense in the condensed consolidated statements of operations.

For stock-based awards that vest over a specific service period, compensation expense is measured based on the fair value of the awards at the grant date and is recognized on a straight-line basis over the service period of the awards, net of an estimated forfeiture rate. For equity instruments that vest based on achievement of a performance condition or both a performance and market condition, stock-based compensation expense is recognized over the service period of the awards based on the expected achievement of the related performance conditions at the end of each reporting period. If the Company's initial estimates of the achievement of the performance conditions change, the related stock-based compensation expense may fluctuate from period to period based on those estimates. If the performance conditions are not met, no stock-based compensation expense will be recognized and any previously recognized stock-based compensation expense will be reversed. For awards with both a performance and a market condition, the Company estimates the fair value of each equity instrument granted on the date of grant using a Monte-Carlo simulation model. This pricing model uses multiple simulations to evaluate

the probability of achieving the market condition to calculate the fair value of the awards, which includes the recent market price and volatility of the Company's shares. When determining the grant date fair value of all stock-based awards, the Company considers whether it is in possession of any material, non-public information that upon its release would have a material effect on its share price, and if so, whether the observable share price or expected volatility assumptions used in determining the fair value of the awards should be adjusted.

The Company estimates the fair value of its performance-based restricted stock awards with market conditions on the date of grant using a Monte-Carlo simulation valuation model. This pricing model uses multiple simulations to evaluate the probability of achieving the market condition to calculate the fair value of the awards. Expense is only recorded for awards that are expected to vest, net of estimated forfeitures.

Loss Contingencies and Litigation Expense

The Company is subject to the possibility of losses from various contingencies, including certain legal proceedings. Significant judgment is necessary to estimate the probability and amount of a loss, if any, from such contingencies. An accrual is made when it is probable that a liability has been incurred or an asset has been impaired, and the amount of loss can be reasonably estimated. In accounting for the resolution of contingencies, significant judgment may be necessary to estimate amounts pertaining to periods prior to the resolution that are charged to operations in the period of resolution and amounts related to future periods. If only a range of estimated losses can be determined, the Company records an amount within the range that, in its judgment, reflects the most likely outcome; if none of the estimates within that range are a better estimate than any other amount, the Company records the low end of the range. Any such accrual would be charged to expense in the appropriate period.

Cash, Cash Equivalents, and Restricted Cash

The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. Restricted cash consists of cash deposited as collateral related to a litigation bond in a third-party insured account.

Allowance for Credit Losses

The Company maintains an allowance for credit losses to cover its current expected credit losses on its trade receivables and contract assets arising from the failure of customers to make contractual payments. The Company estimates credit losses expected over the life of its trade receivables and contract assets based on historical information combined with current conditions that may affect a customer’s ability to pay and reasonable and supportable forecasts. While the Company uses various credit quality metrics, it primarily monitors collectability by reviewing the duration of collection pursuits on its delinquent trade receivables and historical write-off trends. Based on the Company’s experience, the customer's delinquency status, which is analyzed periodically, is the strongest indicator of the credit quality of the underlying trade receivables. The Company’s policy is to write off trade receivables when they are deemed uncollectible.

Under the CECL impairment model, the Company develops and documents its allowance for credit losses on its trade receivables based on five portfolio segments. The determination of portfolio segments is based primarily on the qualitative consideration of the nature of the Company’s business operations and the characteristics of the underlying trade receivables, as follows:

•CoStar Portfolio Segment - The CoStar portfolio segment consists of two classes of trade receivables based on geographical location: North America and International.

•Information Services Portfolio Segment - The Information Services portfolio segment consists of four classes of trade receivables: CoStar Real Estate Manager; Hospitality, North America; Hospitality, International, and other Information Services.

•Multifamily Portfolio Segment - The Multifamily portfolio segment consists of one class of trade receivables.

•LoopNet Portfolio Segment - The LoopNet portfolio segment consists of one class of trade receivables.

•Other Revenues Portfolio Segment - The Other Revenues portfolio segment consists of two classes of trade receivables: Matterport and other marketplaces.

The majority of Residential revenue is e-commerce based and does not result in accounts receivable. Residential accounts receivable and the related allowance for credit losses are not material.

Inventories

Inventories consist primarily of finished goods, assemblies, and raw materials. Assemblies are generally purchased from contract manufacturers. Inventories are valued at the lower of cost or net realizable value. Costs are determined using standard cost, which approximates actual cost on a first-in, first-out basis. The Company assesses the valuation of inventory and periodically adjusts the value for estimated excess and obsolete inventory based upon estimates of future demand and market conditions, as well as damaged or otherwise impaired goods. Inventories are included in prepaid expenses and other current assets on the Company's condensed consolidated balance sheets.

Leases

The determination of whether an arrangement contains a lease and the classification of a lease, if applicable, is made at the commencement of the arrangement, at which time the Company also measures and recognizes a ROU asset, representing the Company’s right to use the underlying asset, and a lease liability, representing the Company’s obligation to make lease payments under the terms of the arrangement. For the purposes of recognizing ROU assets and lease liabilities associated with the Company’s leases, the Company has elected the practical expedient to not recognize a ROU asset or lease liability for short-term leases, which are leases with a term of 12 months or less. The lease term is defined as the noncancellable portion of the lease term, plus any periods covered by an option to extend the lease if it is reasonably certain that the option will be exercised.

In determining the amount of lease payments used in measuring ROU assets and lease liabilities, the Company has elected the practical expedient not to separate non-lease components from lease components for all classes of underlying assets. Consideration deemed part of the lease payments used to measure ROU assets and lease liabilities generally includes fixed payments and variable payments based on either an index or a rate, offset by lease incentives. Upon commencement, the initial ROU asset also includes any lease prepayments. ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. The rates implicit within the Company's leases are generally not determinable. Therefore, the Company's incremental borrowing rate is used to determine the present value of lease payments. The determination of the Company’s incremental borrowing rate requires judgment and is determined at lease commencement and is subsequently reassessed upon a modification to the lease arrangement.

Lease costs related to the Company's operating leases are generally recognized as a single ratable lease cost over the lease term.

Equity Investment

The Company holds an investment in publicly held equity securities in which the Company does not have a controlling interest or exercise significant influence. The equity securities are included in the Equity investment caption on the condensed consolidated balance sheets and are measured at fair value with changes recorded through other income (expense), net on the condensed consolidated statements of operations.

Long-Lived Assets, Intangible Assets and Goodwill

Long-Lived Assets, Intangible Assets, and Goodwill

Long-lived assets, such as property and equipment and purchased intangibles subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The Company capitalizes interest on borrowings during the active construction period of major capital projects. Capitalized interest is added to the cost of the underlying asset and amortized over the estimated useful life of the asset. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to the estimated undiscounted future cash flows expected to be generated by the asset or asset group. If the carrying amount of an asset exceeds its estimated undiscounted future cash flows, an impairment charge is recognized in the amount by which the carrying amount of the asset exceeds the fair value of the asset.

Goodwill is tested for impairment at least annually, on October 1, or more frequently if an event or other circumstance indicates that the fair value of a reporting unit may be below its carrying amount. The Company may first assess qualitative factors to evaluate whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, or elect to bypass the qualitative assessment. If it is determined that it is more likely than not that the fair value of a reporting unit is less than its carrying value, or the Company elects to bypass the qualitative assessment, the Company then performs a quantitative assessment by determining the fair value of each reporting unit. The estimate of the fair value of each reporting unit is based on a projected discounted cash flow model that includes significant assumptions and estimates, including the discount

rate, growth rate, and future financial performance. Assumptions about the discount rate are based on a weighted-average cost of capital for comparable companies. Assumptions about the growth rate and future financial performance of a reporting unit are based on the Company’s forecasts, business plans, economic projections, and anticipated future cash flows. The fair value of each reporting unit is compared to the carrying amount of the reporting unit. If the carrying value of the reporting unit exceeds the fair value, then an impairment loss is recognized for the difference.

Long-Lived Assets, Intangible Assets and Goodwill

Long-Lived Assets, Intangible Assets, and Goodwill

Leasing Operations and Other Income (Expense), Net

In February 2024, the Company closed on the purchase of an office tower and the land on which it rests in Arlington, Virginia. In January 2025, the Company relocated its headquarters from Washington, D.C. to Arlington, VA, initially occupying approximately 30% of the building. The Company intends to build out further space in this building to support anticipated growth and expansion of its operations in the coming years. Maintenance, physical facilities, leasing, property management, and other key responsibilities related to property ownership are outsourced to professional real-estate managers. The office tower measures approximately 550,000 rentable square feet.

The Company accounted for the purchase of this building as an asset acquisition at the cost to acquire, including transaction costs. The Company estimated the fair values of acquired tangible assets (consisting of land, buildings, improvements, and other assets), identified intangible assets and liabilities (consisting of in-place leases and above- and below-market leases), and other liabilities based on its evaluation of information and estimates available at the date of acquisition. Based on these estimates, the Company allocated the total cost to the identified assets acquired and liabilities assumed based on their relative fair value.

The fair value of the building and building improvements consists of the physical structure containing rentable area, as well as amenities such as parking structures, and was valued as if vacant, using the cost approach, which uses replacement cost data obtained from industry recognized guides less depreciation as an input to estimate the fair value, with consideration given to its age, functionality, use classification, construction quality, replacement cost, and accumulated depreciation (effective age vs. economic life). The Company also considered the value of the building using an income approach. The income approach uses market leasing assumptions to estimate the fair value of the property as if vacant, assuming lease-up at prevailing market rental rates over a market-based lease-up period, including deductions for lost-rent during lease-up and leasing costs. The cost and income approaches are reconciled to arrive at an estimated building fair value. The Company assessed the fair value of land based on market comparisons.

The fair values of identified intangible assets and liabilities were determined based on the following:

•The value allocable to the above- or below-market component of an acquired in-place lease is determined based upon the present value (using a discount rate that reflects the risks associated with the acquired lease) of the difference between: (i) the contractual amounts to be received pursuant to the lease over its remaining term and (ii) management's estimate of the amounts that would be received using market rates current at the time of the acquisition for the remaining term of the lease. Amounts allocated to above-market leases are recorded as above-market leases in intangible assets, net in the condensed consolidated balance sheets. These intangible assets are amortized on a straight-line basis as a component of leasing operations to other income (expense), net in the condensed consolidated statements of operations over the remaining terms of the respective leases.

•Factors considered in determining the value allocable to in-place leases during hypothetical lease-up periods related to space that is leased at the time of acquisition include: (i) lost rent and operating cost recoveries during the hypothetical lease-up period and (ii) theoretical leasing commissions required to execute similar leases. These intangible assets are recorded as in-place leases in intangible assets, net in the condensed consolidated balance sheets and are amortized to other income (expense), net in the condensed consolidated statements of operations over the remaining terms of the existing leases.

Debt Issuance Costs

Costs incurred in connection with the issuance of long-term debt are deferred and amortized as interest expense over the term of the related debt using the effective interest method for term debt and on a straight-line basis for revolving debt. The Company made a policy election to classify deferred issuance costs on the revolving credit facility as a long-term asset on its condensed consolidated balance sheets. Upon a refinancing or amendment, previously capitalized debt issuance costs are expensed and included in loss on extinguishment of debt if the Company determines that there has been a substantial modification of the related debt. If the Company determines that there has not been a substantial modification of the related debt, any previously capitalized debt issuance costs are amortized as interest expense over the term of the new debt instrument.

Business Combinations

The Company includes the results of operations of the businesses that it acquires from the date of acquisition. The Company generally allocates the purchase consideration to the tangible assets acquired and liabilities assumed and intangible assets acquired based on their estimated fair values on the date of the acquisition. The purchase price is generally determined based on the fair value of the assets transferred, liabilities assumed, and equity interests issued, after considering any transactions that are separate from the business combination. The excess of the fair value of purchase consideration over the fair values of these identifiable assets and liabilities is recorded as goodwill. The Company applies significant assumptions, estimates, and judgments in determining the fair value of assets acquired and liabilities assumed on the acquisition date, especially with respect to intangible assets and contingent liabilities. Significant estimates in valuing certain intangible assets include, but are not limited to, future expected cash flows from acquired customer bases, acquired technology, acquired trade names, useful lives, royalty rates, and discount rates. Estimates of fair value are based on assumptions believed to be reasonable, but which are inherently uncertain and unpredictable and, as a result, actual results may differ from estimates. Any adjustments to provisional amounts that are identified during the measurement period, not to exceed one year from the date of acquisition, are recorded in the reporting period in which the adjustment amounts are determined. Upon the conclusion of the measurement period, any subsequent adjustments are recorded to earnings.

The Company has elected the practical expedient provided under ASC 805, Business Combinations, which allows for contract assets and liabilities acquired or assumed in an acquisition to be measured in accordance with the accounting framework for revenue from contracts with customers as if the Company had originated the acquired contract. This is an exception to the general requirement to measure assets acquired and liabilities assumed at their fair value on the acquisition date.

For a given acquisition, the Company may identify certain pre-acquisition contingencies as of the acquisition date and may extend its review and evaluation of these pre-acquisition contingencies throughout the measurement period in order to obtain

sufficient information to assess whether the Company includes these contingencies as part of the fair value estimates of assets acquired and liabilities assumed and, if so, to determine their estimated amounts.

If the Company cannot reasonably determine the fair value of a pre-acquisition contingency (non-income tax-related) by the end of the measurement period, which is generally the case given the nature of such matters, the Company will recognize an asset or a liability for such pre-acquisition contingency if: (i) it is probable that an asset existed or a liability had been assumed at the acquisition date and (ii) the amount of the asset or liability can be reasonably estimated. Subsequent to the measurement period, changes in the Company's estimates of such contingencies will affect earnings and could have a material effect on its results of operations and financial position.

In addition, uncertain tax positions and tax-related valuation allowances assumed in connection with a business combination are initially estimated as of the acquisition date. The Company reevaluates these items based upon facts and circumstances that existed as of the acquisition date with any adjustments to its preliminary estimates being recorded to goodwill, provided that the Company is within the measurement period. Subsequent to the measurement period, changes to these uncertain tax positions and tax-related valuation allowances will affect the Company's provision for income taxes in its condensed consolidated statements of operations and comprehensive income and could have a material impact on its results of operations and financial position.

Transaction costs associated with business combinations are expensed as incurred and are included in general and administrative expenses in the condensed consolidated statements of operations.

Recent Accounting Pronouncements and Not Yet Adopted

Recent Accounting Pronouncements

Recent Accounting Pronouncements Not Yet Adopted

In December 2023, the FASB issued ASU No. 2023-09 (Topic 740), Improvements to Income Tax Disclosures (Topic 740). The ASU requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as an expansion of other income tax disclosures. The ASU is effective on a prospective basis for annual reporting periods beginning after December 15, 2024. The Company is currently evaluating the impact this ASU will have on its consolidated financial statements and related disclosures.

In November 2024, the FASB issued ASU No. 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40). The ASU requires incremental disclosures about specific expense categories, including but not limited to, purchases of inventory, employee compensation, depreciation, amortization, and selling expenses. The amendments are effective for fiscal years beginning after December 15, 2026 and for interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted and the amendments may be applied either prospectively or retrospectively. Management is currently evaluating this ASU to determine its impact on the Company's disclosures.