Document and Entity Information - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Jun. 30, 2026 |
Aug. 21, 2026 |
Dec. 31, 2025 |
|
| Cover [Abstract] | |||
| Document Type | 10-K | ||
| Amendment Flag | false | ||
| Document Period End Date | Jun. 30, 2026 | ||
| Document Fiscal Year Focus | 2026 | ||
| Document Fiscal Period Focus | FY | ||
| Trading Symbol | QNST | ||
| Entity Registrant Name | QuinStreet, Inc. | ||
| Entity Central Index Key | 0001117297 | ||
| Current Fiscal Year End Date | --06-30 | ||
| Entity Well-known Seasoned Issuer | Yes | ||
| Entity Current Reporting Status | Yes | ||
| Entity Voluntary Filers | No | ||
| Entity Filer Category | Large Accelerated Filer | ||
| Entity Common Stock, Shares Outstanding | 57,086,409 | ||
| Entity Public Float | $ 779,144,648 | ||
| ICFR Auditor Attestation Flag | true | ||
| Document Financial Statement Error Correction [Flag] | false | ||
| Entity Shell Company | false | ||
| Entity Small Business | false | ||
| Entity Emerging Growth Company | false | ||
| Entity File Number | 001-34628 | ||
| Entity Tax Identification Number | 77-0512121 | ||
| Entity Address, Address Line One | 950 Tower Lane | ||
| Entity Address, Address Line Two | 12th Floor | ||
| Entity Address, City or Town | Foster City | ||
| Entity Address, State or Province | CA | ||
| Entity Incorporation State Country Code | DE | ||
| Entity Address, Postal Zip Code | 94404 | ||
| City Area Code | 650 | ||
| Local Phone Number | 587-7700 | ||
| Title of 12(b) Security | Common Stock, par value $0.001 per share | ||
| Security Exchange Name | NASDAQ | ||
| Documents Incorporated by Reference | Portions of the registrant’s definitive proxy statement relating to its 2026 annual stockholders’ meeting are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated | ||
| Document Annual Report | true | ||
| Document Transition Report | false | ||
| Entity Interactive Data Current | Yes | ||
| Auditor Name | PricewaterhouseCoopers LLP | ||
| Auditor Location | San Jose, California | ||
| Auditor Firm ID | 238 | ||
| Auditor Opinion | Opinions on the Financial Statements and Internal Control over Financial Reporting We have audited the accompanying consolidated balance sheets of QuinStreet Inc. and its subsidiaries (the “Company”) as of June 30, 2026 and 2025, and the related consolidated statements of operations and comprehensive income (loss), of stockholders’ equity and of cash flows for each of the three years in the period ended June 30, 2026, including the related notes (collectively referred to as the “consolidated financial statements”). We also have audited the Company's internal control over financial reporting as of June 30, 2026, based on criteria established in Internal Control - Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the financial position of the Company as of June 30, 2026 and 2025, and the results of its operations and its cash flows for each of the three years in the period ended June 30, 2026 in conformity with accounting principles generally accepted in the United States of America. Also in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of June 30, 2026, based on criteria established in Internal Control - Integrated Framework (2013) issued by the COSO. |