Response uses compression

medium

compression

Checks if the response uses gzip or brotli compression.

What does this rule check?

HTTP compression reduces the size of transferred data by 60-80%. Gzip is universally supported. Brotli offers even better compression but requires HTTPS.

Why is this important?

Without compression, the browser downloads full uncompressed files, significantly slowing page load. Compression is one of the easiest performance wins.

How to fix

Enable gzip or brotli compression on your web server or CDN.

Examples

Incorrect 
Content-Encoding: (none)
<!-- 500KB transferred uncompressed -->
Correct 
Content-Encoding: gzip
<!-- 120KB transferred compressed -->

Agent fix snippet

Copy this snippet and paste it into your AI coding agent to fix this issue automatically.

Enable compression on your server:

Nginx: gzip on;
Apache: AddOutputFilterByType DEFLATE text/html
Node.js: use compression middleware