Gzip Compression Test
Check whether a site enables Gzip/Brotli compression and if page size is optimized.
The WebURL Gzip Test is a free online tool, no signup required, that checks whether a site serves Gzip/Brotli compression and measures HTML transfer size — use it to diagnose slow page loads.
About this tool
The GZIP test requests your URL with compression enabled and reports original size versus compressed size, plus the ratio. Page weight directly affects load speed, and compression is usually the highest-ROI optimization available.
How to read results: HTML text typically shrinks by 70-80% when compressed. If the test shows uncompressed, check your server config (Nginx gzip directives / Apache mod_deflate) or your CDN's compression toggle.
Note: already-compressed formats like images and video see little benefit - GZIP targets text resources: HTML, CSS, JS and JSON.
Frequently asked questions
How does the GZIP compression test work?
The tool sends a request to your URL with gzip encoding enabled and reports the original size versus the compressed size, plus the compression ratio. It works entirely from your browser and shows results in real time.
Why does GZIP matter for SEO?
Compressed pages load faster, and page speed is a ranking factor on both Google and Bing. Enabling GZIP typically cuts HTML size by 70 to 80 percent, which is one of the easiest performance wins for any website.
How do I enable GZIP on my server?
On Nginx add gzip on and related directives to your config; on Apache enable mod_deflate; most CDNs like Cloudflare enable compression automatically. After changing the config, reload the server and re-run this test to confirm.