Website Gzip Checker
Test the most basic speed setting of a web server. The checker requests the page with Accept-Encoding: gzip, reads whether the response is gzip-compressed and how many bytes were transferred, compares that with the uncompressed size and Brotli, and lists the Content-Encoding of the page’s CSS and JavaScript files so you can spot assets served without compression.
- Encrypted connection
- No sign-up
- Free to use
How to use Website Gzip Checker
- Enter the page address.
- Click “Check gzip”.
- See whether gzip is on and the savings.
- Fix uncompressed assets.
Website Gzip Checker features
Real request
Accept-Encoding: gzip.
Savings
Bytes and percent.
Assets
CSS and JavaScript.
Measured, not guessed
Real transfer sizes from our server.
Safe fetching
Public addresses only, with size and time limits.
Brotli comparison
Shown alongside.
When to use Website Gzip Checker
- Checking shared hosting.
- Diagnosing slow pages.
- Server configuration reviews.
- Before a launch.
Website Gzip Checker FAQ
Why does the server choose the encoding?
Browsers say which encodings they accept; the server picks one. Checking each encoding separately shows what it supports.
Should images be compressed with gzip?
No – JPEG, PNG, WebP and video are already compressed; gzip only helps text files.
What if gzip is off?
Enable it in the server or hosting panel; on Apache use mod_deflate, on Nginx the gzip directive.
Is deflate the same?
deflate is an older, rarely used variant; gzip and Brotli are the standards.
gzip basics
gzip compression has been supported by every browser for decades and usually cuts text transfer sizes by 70% or more. A server without it is leaving easy speed on the table.
Compression costs little CPU compared with the bandwidth it saves.
How it works: our server downloads the page once through a guarded fetcher that only connects to public addresses, follows a limited number of redirects and stops after a size and time limit. The HTML is then analysed in your browser as inert text – scripts on the page never run and nothing is stored.
What it cannot see: content and resources that a page adds with JavaScript after it loads, pages behind a login, and servers that block automated requests. For those, open the page in your browser, use its developer tools, or paste the page source where the tool offers a paste option.
Use the results as a starting point: fix the items marked red first, review the yellow warnings in context, and run the check again after a change. Requests are rate-limited to keep the service fair; if you check many pages in a row, wait a few minutes.
Related checks on this site cover the rest of a technical review – speed and Core Web Vitals, security headers, structured data, accessibility and SEO signals – so you can work through a whole site audit one topic at a time.
Who it is for: site owners checking their own pages, developers debugging a release, SEO and marketing teams auditing clients or competitors, and students learning how the web works. No account or installation is needed, and the results are plain text and tables you can copy into a report or ticket.