Browser security
Compatibility & evidence
Content execution

CSP upgrade-insecure-requests

Asks the browser to rewrite eligible insecure resource requests to HTTPS.

Support in current browsers

Checked against the current browser versions recorded in MDN browser data 8.1.5.

BrowserMinimumOutcomeReason
Chrome155WorksEvery required mapped BCD feature is available without a recorded qualification.
Edge154WorksEvery required mapped BCD feature is available without a recorded qualification.
Firefox157WorksEvery required mapped BCD feature is available without a recorded qualification.
Safari27WorksEvery required mapped BCD feature is available without a recorded qualification.
Chrome for Android155WorksEvery required mapped BCD feature is available without a recorded qualification.
Firefox for Android157WorksEvery required mapped BCD feature is available without a recorded qualification.
Safari on iOS27WorksEvery required mapped BCD feature is available without a recorded qualification.
Android WebView155WorksEvery required mapped BCD feature is available without a recorded qualification.
Samsung Internet30.0WorksEvery required mapped BCD feature is available without a recorded qualification.
The release trace

How support changed

Each segment groups recorded releases with the same result. Gaps between recorded versions are not filled in. This is support at each release, rather than the planner’s check of every release above a minimum.

Chrome

http.headers.Content-Security-Policy.upgrade-insecure-requests
  1. 1 – 4242 recorded releases
    Not supported
  2. 43 – 155112 recorded releases
    Works

Edge

http.headers.Content-Security-Policy.upgrade-insecure-requests
  1. 12 – 165 recorded releases
    Not supported
  2. 17 – 15477 recorded releases
    Works

Firefox

http.headers.Content-Security-Policy.upgrade-insecure-requests
  1. 1 – 4144 recorded releases
    Not supported
  2. 42 – 157116 recorded releases
    Works

Safari

http.headers.Content-Security-Policy.upgrade-insecure-requests
  1. 1 – 1016 recorded releases
    Not supported
  2. 10.1 – 2745 recorded releases
    Works

Chrome for Android

http.headers.Content-Security-Policy.upgrade-insecure-requests
  1. 18 – 4219 recorded releases
    Not supported
  2. 43 – 155112 recorded releases
    Works

Firefox for Android

http.headers.Content-Security-Policy.upgrade-insecure-requests
  1. 4 – 4135 recorded releases
    Not supported
  2. 42 – 157106 recorded releases
    Works

Safari on iOS

http.headers.Content-Security-Policy.upgrade-insecure-requests
  1. 1 – 1013 recorded releases
    Not supported
  2. 10.3 – 2745 recorded releases
    Works

Android WebView

http.headers.Content-Security-Policy.upgrade-insecure-requests
  1. 1 – 4214 recorded releases
    Not supported
  2. 43 – 155112 recorded releases
    Works

Samsung Internet

http.headers.Content-Security-Policy.upgrade-insecure-requests
  1. 1.0 – 3.27 recorded releases
    Not supported
  2. 4.0 – 30.045 recorded releases
    Works

BCD 8.1.5 · catalogue 2.3.0. Source corrections can change this trace without a new browser release.

What this feature can and cannot do

Helps protect against

  • Mixed-content downgrade
  • Accidental insecure subresource requests

Does not guarantee

  • Unavailable HTTPS resources
  • Insecure external redirects
  • Transport setup

What you need before using it

  • HTTPS availability for every upgraded resource

Fallback to keep in place

Migrate every resource URL to HTTPS and block mixed content explicitly.