Gzip & Brotli Compression Test
Check whether a page is served with Gzip or Brotli and how much it saves.
About the Gzip & Brotli Compression Test
Text files – HTML, CSS, JavaScript, JSON and SVG – compress extremely well. Gzip typically shrinks them by 70–80%, and Brotli, supported by every modern browser, saves another 15–20% on top. Enabling compression is one of the easiest speed wins, and it is often a single setting on your server or CDN.
This test requests the page three times – asking for Brotli, Gzip and no compression – and shows which encodings your server supports and exactly how many bytes each one saves.
Frequently asked questions
How do I enable compression?
On Apache, enable mod_deflate (and mod_brotli if available); on Nginx, turn on gzip and the brotli module; on cPanel use “Optimize Website”. CDNs such as Cloudflare compress automatically.
Should images be compressed with Gzip?
No. JPEG, PNG, WebP and AVIF are already compressed. Gzip only helps text-based files.
Does compression slow the server?
Barely. Compression uses a little CPU, but the bandwidth and time saved are far greater. Static files can be pre-compressed.