Gzip Compression Test
Request a URL with gzip accepted and check whether the server compresses the response.
- Runs on our servers
- Free to use
About this tool
The Gzip Compression Test sends a request for the URL with Accept-Encoding: gzip and checks the Content-Encoding of the response. It tells you in one line whether compression is active for that resource, something many site owners assume without verifying.
Run it on an HTML page, a stylesheet and a script to make sure all text assets are compressed, then check Brotli and HTTP/2 support too.
How to use it — quick steps
- 01
Enter the url
Type or paste the url in the field above, for example https://www.example.com/
- 02
Press "Test gzip"
Press "Test gzip" or Ctrl + Enter. The result appears below in a few seconds. Results can be copied.
- 03
Read the result
It appears in the dark panel under the form in a few seconds. Every block has [copy] and other actions.
Key features of this tool
External lookups
The lookup runs from our infrastructure, so you see what the public internet sees without exposing your own IP address or network.
Fast and cached
Results come back in seconds; identical lookups are cached for a few minutes to keep the service fast and responsive for everyone.
Easy to reuse
Every result block can be copied with one click or downloaded as a text file, and tables can also be saved as CSV for your reports.
Frequently asked questions
What does gzip compression do?
It shrinks text responses (HTML, CSS, JavaScript, JSON) by 60–80% before they leave the server, cutting transfer time for every visitor.
Gzip is enabled but the test says no
Compression is often enabled per content type or size; test an HTML page rather than an image, and make sure the proxy or CDN in front of the server does not strip Accept-Encoding.
Should I use Brotli instead?
Brotli compresses better and is supported by all modern browsers; most servers offer both and let the client choose. Test it with the Brotli Compression Test.