What This Tool Checks
HeaderCheckr follows safe redirects, inspects the final response, and reports the content encoding advertised by the server or CDN.
Web Debugging
Compression Checker
Detect gzip, brotli, and other response encodings on the final URL.
Guide
Compression Checks
Compression reduces the amount of text data browsers need to download before rendering a page.
This checker confirms whether the final response is compressed and whether the caching headers make that compression clear.
Why It Matters
Brotli and gzip can make HTML, CSS, JavaScript, JSON, and SVG responses smaller, which improves load time on slower networks.
Missing compression is not always a problem for images or PDFs, but it is usually worth fixing for text-based pages and assets.
Related Tools
After checking compression, inspect redirect chains, HTTP protocol support, and security headers.
FAQ
Is brotli better than gzip?
Brotli often compresses text assets smaller than gzip, especially for static files. Gzip is still widely supported and useful as a fallback.
Should every file be compressed?
No. Compress text responses such as HTML, CSS, JavaScript, JSON, and SVG. Images, video, archives, and PDFs are usually already compressed.
Why might compression be missing?
Common causes include CDN rules, origin server settings, file type exclusions, very small responses, or proxies stripping the Content-Encoding header.