Gzip and Brotli

Gzip and Brotli are compression algorithms for text assets such as HTML, CSS, JavaScript, JSON, and SVG. The server compresses, the browser decompresses, and the transfer gets smaller and faster.

The short difference

How to enable it

• LiteSpeed/cPanel: usually on by default; check the Content-Encoding response header.
• Nginx: enable gzip on; and the Brotli module if available.
• CDN: many CDNs compress automatically at the edge.
• WordPress: a cache plugin usually handles HTML and static assets.

Test with `curl -I -H "Accept

• Encoding: br,gzip" https://example.com` and look at the Content-Encoding header.

What to watch for

• Do not compress images/video. Those formats are already compressed; the result can be larger.
• Avoid double compression. If the CDN already compresses, the origin does not need to do it again.
• Watch Content-Length. Compression changes the size; do not cache the wrong header.
• Brotli needs HTTPS in many setups. Make sure the connection is secure.
• Compression costs CPU. On a small server, measure the impact before raising the compression level.

Already-compressed files such as JPEG, PNG, WebP, MP4, and ZIP should not be compressed again. Compression helps large JSON API responses; for very small responses, header overhead can outweigh the saving. Measure with DevTools or curl before changing the configuration.

FAQ