← All checks
SecurityTypical severity: Low

Subresource Integrity Scanner

Detects scripts and styles loaded from external CDNs without the integrity attribute that verifies them.

What it checks

This scanner reviews the scripts and stylesheets your page loads from CDNs or external origins and checks whether they include the integrity attribute. That attribute lets the browser verify that the file it received is exactly the one expected.

Why it matters

Without the integrity attribute, if the external CDN is compromised or tampered with, your site would run modified code without noticing. An attacker could inject malicious scripts that steal your users' data straight from their browser.

How to fix it

Add the integrity attribute with the file's hash to every script and style you load from an external origin, along with crossorigin. Many tools and the CDNs themselves provide the hash ready to copy, or you can self-host the resource instead.

Check it on your site

Scan your site free and see if this and 44 other checks pass, with a fix prompt for every issue.

Scan my site free

Related checks