v3.25.4
Document and Entity Information - USD ($)
$ in Millions
 12 Months Ended
Jan. 03, 2026
Feb. 26, 2026
Jun. 27, 2025
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Jan. 03, 2026    
Document Transition Report false    
Entity File Number 001-33264    
Entity Registrant Name CARPARTS.COM, INC.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 68-0623433    
Entity Address, Address Line One 4910 Airport Plaza Drive    
Entity Address, Address Line Two Suite 300    
Entity Address, City or Town Long Beach    
Entity Address, State or Province CA    
Entity Address, Postal Zip Code 90815    
City Area Code 424    
Local Phone Number 702-1455    
Title of 12(b) Security Common Stock, $0.001 par value per share    
Trading Symbol PRTS    
Security Exchange Name NASDAQ    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Smaller Reporting Company true    
Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 41.2
Entity Common Stock, Shares Outstanding   70,477,662  
Documents Incorporated by Reference [Text Block]

Portions of our proxy statement for the 2025 Annual Meeting of Stockholders (the “Proxy Statement”) are incorporated by reference in Part III hereof. Except with respect to information specifically incorporated by reference in this Form 10-K, the Proxy Statement is not deemed to be filed as a part hereof.

    
Entity Central Index Key 0001378950    
Current Fiscal Year End Date --01-03    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Amendment Flag false    
Auditor Firm ID 49    
Auditor Name RSM US LLP    
Auditor Location Irvine, California