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.


Upgrade-Insecure-Requests: 1


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


Specification Status Comment
Upgrade Insecure Requests
The definition of 'upgrade-insecure-requests' in that specification.
Candidate Recommendation Initial definition.

Browser compatibility

Feature Chrome Edge Firefox Internet Explorer Opera Safari
Basic support 44 No1 48 No 31 ?
Feature Android webview Chrome for Android Edge mobile Firefox for Android IE mobile Opera Android iOS Safari
Basic support ? 44 No 48 ? 31 ?

1. Under consideration for future release.

See also

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