| Document and Entity Information Document | Dec. 07, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Dec. 7, 2020 |
| Entity Registrant Name | STITCH FIX, INC. |
| Entity File Number | 001-38291 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 27-5026540 |
| Entity Address, Address Line One | 1 Montgomery Street |
| Entity Address, Address Line Two | Suite 1500 |
| Entity Address, City or Town | San Francisco |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94104 |
| City Area Code | 415 |
| Local Phone Number | 882-7765 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Class A common stock, par value $0.00002 per share |
| Trading Symbol | SFIX |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001576942 |
| Amendment Flag | false |
| Entity Addresses [Line Items] | |
| Entity Address, Address Line One | 1 Montgomery Street |
| Entity Address, Address Line Two | Suite 1500 |
| Entity Address, City or Town | San Francisco |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94104 |
