The HTTP Upgrade-Insecure-Requests request header sends a signal to the server expressing the client’s preference for an encrypted and authenticated response, and that it can successfully handle the upgrade-insecure-requests CSP directive.
| Header type | Request header |
|---|---|
| Forbidden header name | no |
Syntax
Upgrade-Insecure-Requests: 1
Examples
A client requests signals to the server that it supports the upgrade mechanisms of upgrade-insecure-requests:
GET / HTTP/1.1 Host: example.com Upgrade-Insecure-Requests: 1
The server can now redirect to a secure version of the site. A Vary header can be used so that the site isn't served by caches to clients that don’t support the upgrade mechanism.
Location: https://example.com/ Vary: Upgrade-Insecure-Requests
Specifications
| Specification | Status | Comment |
|---|---|---|
| Upgrade Insecure Requests The definition of 'upgrade-insecure-requests' in that specification. |
Candidate Recommendation | Initial definition. |
Browser compatibility
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
| Feature | Chrome | Firefox | Edge | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| Basic Support | 44 | 48.0 | (No)1 | (No) | 31 | ? |
| Feature | Android | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
|---|---|---|---|---|---|---|---|
| Basic Support | ? | 44 | (No) | 48.0 | ? | 31 | ? |
1. Under consideration for future release.
See also
Content-Security-Policy- CSP
upgrade-insecure-requestsdirective