SRI Browser Compatibility Guide

SRI Browser Compatibility

Subresource Integrity is supported by all modern browsers. Understanding the support landscape helps you implement SRI confidently and handle edge cases in older environments.

Current Browser Support

As of 2024, SRI is supported in:

Browser	Version	Released
Chrome	45+	Sep 2015
Firefox	43+	Dec 2015
Safari	11+	Sep 2017
Edge	17+	Apr 2018
Opera	32+	Sep 2015
Samsung Internet	5.0+	2017

Global support: ~97% of all browsers (based on caniuse.com data).

Unsupported Browsers

The following browsers do not support SRI:

• Internet Explorer (all versions)
• Opera Mini
• UC Browser (older versions)
• Very old mobile browsers

Graceful Degradation

SRI is designed to degrade gracefully. In browsers that do not support the integrity attribute:

1. The attribute is ignored
2. The resource loads normally without integrity checking
3. No errors are thrown
4. The page functions as if the attribute were not present

This means adding SRI is never harmful — it can only improve security, never break functionality.

<!-- Works in all browsers; SRI verification only in supporting ones -->
<script
  src="https://cdn.example.com/lib.js"
  integrity="sha384-..."
  crossorigin="anonymous"
></script>

Feature Detection

If you need to detect SRI support programmatically:

function supportsSRI() {
  const link = document.createElement('link');
  return 'integrity' in link;
}

if (supportsSRI()) {
  console.log('SRI is supported');
} else {
  console.log('SRI not supported; consider additional security measures');
}

Mobile Browser Considerations

Mobile browser support generally mirrors desktop versions:

• Chrome for Android: supports SRI (same engine as desktop Chrome)
• Safari on iOS: supports SRI since iOS 11
• Firefox for Android: supports SRI
• WebView (Android): supports SRI since Android 7.0+

Enterprise and Legacy Environments

In enterprise environments where Internet Explorer may still be in use:

• SRI attributes will be ignored by IE — the resources will still load
• Consider additional security measures for IE users: CSP headers, server-side integrity verification, or upgrading browser requirements
• Document in your security policy that SRI protection is not available in IE

Testing SRI Across Browsers

1. Use BrowserStack or Sauce Labs to test SRI behavior across browser versions
2. Verify that the resource loads correctly in supporting browsers
3. Verify that the resource still loads (without SRI) in older browsers
4. Test SRI failure scenarios (modified file) to confirm blocking behavior
5. Check console error messages for developer-friendly debugging information