Fetch metadata request headersLimited availability
The Sec-Fetch-Dest, Sec-Fetch-Mode, Sec-Fetch-Site, and Sec-Fetch-User HTTP headers provide extra information about the way a request was made, to help servers reject certain kinds of malicious requests.
Not yet supported in all major browsers — check the table and provide a fallback.
Browser support
DesktopChrome
1–79Not supported
80+Supportedsince Feb 4, 2020
Current: 155Edge
12–79Not supported
80+Supportedsince Feb 7, 2020
Current: 154Firefox
1–89Not supported
90+Supportedsince Jul 13, 2021
Current: 157Safari
✕Not supportedup to 27
Current: 27MobileChrome Android
18–79Not supported
80+Supportedsince Feb 4, 2020
Current: 155Firefox Android
4–89Not supported
90+Supportedsince Jul 13, 2021
Current: 157Safari iOS
✕Not supportedup to 27
Current: 27How to use
Not supported in Safari, Safari iOS. Use feature detection below and provide a fallback (or a polyfill) for those browsers.
Example
Full syntax and examples are on MDN: Sec-Fetch-Dest.
Feature detection
There’s no simple runtime check for this feature; rely on the support table and test in your target browsers.
Documentation (MDN)
Specification
Sub-features
Support for each part of the feature (4). The overall table above shows when the whole feature works.
| Sub-feature | Chrome | Edge | Firefox | Safari | Chrome Android | Firefox Android | Safari iOS |
|---|---|---|---|---|---|---|---|
| http.headers.Sec-Fetch-Dest | 80 | 80 | 90 | 16.4 | 80 | 90 | 16.4 |
| http.headers.Sec-Fetch-Mode | 76 | 79 | 90 | 16.4 | 76 | 90 | 16.4 |
| http.headers.Sec-Fetch-Site | 76 | 79 | 90 | 16.4 | 76 | 90 | 16.4 |
| http.headers.Sec-Fetch-User | 76 | 79 | 90 | ✕ | 76 | 90 | ✕ |