Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

Document and Entity Information - shares
9 Months Ended
Sep. 30, 2017
Oct. 30, 2017
Document And Entity Information [Abstract]    
Entity Registrant Name U.S. Auto Parts Network, Inc.  
Entity Central Index Key 0001378950  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Document Type 10-Q  
Document Period End Date Sep. 30, 2017  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus (Q1,Q2,Q3,FY) Q3  
Trading Symbol PRTS  
Amendment Flag false  
Entity Common Stock, Shares Outstanding   35,528,610