Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

Document and Entity Information - shares
6 Months Ended
Jul. 04, 2015
Aug. 05, 2015
Document And Entity Information [Abstract]    
Document Type 10-Q  
Document Period End Date Jul. 04, 2015  
Amendment Flag false  
Document Fiscal Year Focus 2015  
Document Fiscal Period Focus Q2  
Trading Symbol PRTS  
Entity Registrant Name U.S. Auto Parts Network, Inc.  
Entity Central Index Key 0001378950  
Current Fiscal Year End Date --01-02  
Entity Filer Category Non-accelerated Filer  
Entity Common Stock, Shares Outstanding   34,001,972