v3.8.0.1
Document and Entity Information - shares
9 Months Ended
Apr. 28, 2018
Jun. 05, 2018
Document Information [Line Items]    
Document type 10-Q  
Amendment flag false  
Document period end date Apr. 28, 2018  
Document fiscal year focus 2018  
Document fiscal period focus Q3  
Trading Symbol SFIX  
Entity registrant name Stitch Fix, Inc.  
Entity central index key 0001576942  
Current fiscal year end date --07-28  
Entity filer category Non-accelerated Filer  
Class A Common Stock    
Document Information [Line Items]    
Entity common stock, shares outstanding   27,725,150
Class B Common Stock    
Document Information [Line Items]    
Entity common stock, shares outstanding   70,142,861