Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

Document and Entity Information - shares
6 Months Ended
Jun. 29, 2019
Aug. 07, 2019
Document And Entity Information [Abstract]    
Document Type 10-Q  
Document Period End Date Jun. 29, 2019  
Entity Registrant Name U.S. AUTO PARTS NETWORK, INC.  
Entity Current Reporting Status Yes  
Entity Filer Category Non-accelerated Filer  
Smaller Reporting Company true  
Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   35,824,188
Current Fiscal Year End Date --12-28  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Entity Central Index Key 0001378950  
Amendment Flag false