Brotli vs Gzip: Which Compression Should You Use?

Text compression is one of the simplest performance wins available: your server shrinks HTML, CSS and JavaScript before sending them, and the browser expands them back on arrival. The two dominant methods are Gzip, the long-standing default, and Brotli, the newer format that usually compresses text smaller. In practice you should offer both.

How text compression works

Text files are full of repetition: the same tags, class names, and keywords appear over and over. Compression algorithms replace those repeated patterns with short references, so a 100 KB stylesheet might travel as 20 KB. The browser announces which formats it accepts with the Accept-Encoding request header, and the server replies with the format it used in Content-Encoding. Fewer bytes on the wire means the page arrives sooner, especially on mobile connections.

Where Brotli wins

Brotli generally achieves a better compression ratio than Gzip for text, particularly at higher quality levels, partly because it ships with a built-in dictionary of common web strings. For static assets you compress once and cache, you can use Brotli’s highest setting and store the result — the extra compression time is paid a single time, and every visitor downloads the smaller file.

For dynamic responses generated on each request, a mid-range quality level balances compression against CPU cost. The right trade-off depends on how often the content changes.

Where Gzip still matters

Gzip remains valuable as a fallback. It is universally supported, fast, and handles the rare client that does not advertise Brotli. A correct setup offers Brotli first and falls back to Gzip automatically based on the browser’s Accept-Encoding header — you are not choosing one or the other.

Quick comparison

How to enable them

On Nginx, enable the gzip module and add the Brotli module, listing the text MIME types to compress:

gzip on;
gzip_types text/plain text/css application/javascript application/json;

brotli on;
brotli_types text/plain text/css application/javascript application/json;

On Apache, use mod_deflate for Gzip and mod_brotli for Brotli. Behind a CDN like Cloudflare, Brotli is often available with a single toggle at the edge — see our CDN guide. Whatever the platform, compress only text-based types.

Frequently asked questions

Related guides