gzip Compression Checker

Check whether gzip compression is enabled

Features

Instantly determine whether compression is applied

Just enter a URL to instantly check the compression state when served

Display size before and after compression

Measure the byte count after compression and after decompression to visualize transfer volume

Automatically calculate the compression ratio

Show the amount of data reduced from the difference before and after compression as a percentage

Support for methods other than gzip

Also detects deflate and Brotli compression and shows the method name

How to use

Enter a URL in the input field

Enter the URL of the page whose compression state you want to check in the input field

Run the check button

Press the check button and the server fetches the page to determine the result

Check the result and details

Check the enabled/disabled result along with header information such as size and compression ratio

Use cases

Checking display speed improvements

Inspect whether compression is applied to understand the room for faster loading through reduced transfer volume

Verifying server settings

Check whether settings are correctly applied after enabling compression

Researching competitor sites

Compare other sites' compression settings and ratios as a reference for improvement

Pre-inspection for SEO improvement

Understand the compression state that affects page speed before taking measures

Basic Knowledge

What is gzip compression?

gzip is a mechanism where the server compresses text such as HTML and CSS before sending it to the browser, reducing the size to approximately one-third, which speeds up display and reduces data usage. The receiving browser automatically decompresses it, so the appearance remains unchanged.

Other compression methods like Brotli

In recent years, Brotli (br), which has a higher compression ratio than gzip, is also widely used. You can check which compression method was used by looking at the Content-Encoding value in the response header.