Text compression with gzip: Crawl Audit check 89

Short answer: text files such as HTML, CSS and JavaScript shrink a lot when compressed, and every modern browser can unpack them. Check 89 passes when your homepage's HTML arrives with any of the common compressions (gzip, Brotli or Zstandard), and warns when it arrives uncompressed.

What Crawl Audit checks

• Crawl Audit reads the Content-Encoding header on your homepage's HTML.
• Pass: it contains gzip, br (Brotli) or zstd (Zstandard). Warning: no compression header.

Check 90 then asks whether it's Brotli specifically.

What the standards say

• MDN lists the values: gzip, "A format using the Lempel-Ziv coding (LZ77), with a 32-bit CRC"; br, "A format using the Brotli algorithm structure (defined in RFC 7932)"; zstd, "A format using the Zstandard algorithm structure (defined in RFC 8878)".
• Lighthouse: "Text-based resources should be served with compression to minimize total network bytes."
• Images and video are already compressed: "Compressing already compressed media types, such as .zip or .jpeg, is usually not appropriate because it can increase the file size."

How to check yours

In your browser's developer tools, open the Network tab, reload, click the page's own request and look for content-encoding in the response headers.

On devmarde.com

Our homepage arrives as br (Brotli) from Vercel, so it passes this check and check 90.

On your platform

• Vercel: "supporting both Gzip and Brotli compression", on by default.
• Cloudflare: "Cloudflare supports Gzip, Brotli, and Zstandard compression", on by default.
• Shopify, Wix and Squarespace: handled by the platform.
• Your own server: turn on gzip (and Brotli if available) in nginx, Apache or your host's panel.

Sources

• MDN, Content-Encoding, checked 3 October 2026.
• Chrome for Developers, Enable text compression.
• Vercel, Compression; Cloudflare, Compression.