GZIP or Brotli compression missing: Performance fix

Check compression on the actually transmitted response

An existing file such as styles.css.gz does not yet prove that the web server delivers it. Decisive is the answer to the requested CSS, JavaScript or HTML URL. An upstream CDN can also provide a different version than the original server.

Example: Recognizing the Result

Illustrative example: A 180 KB CSS file is transferred when retrieved with Accept encoding without content encoding. One next to it . gz file is not used automatically.

GET /assets/site.css
Accept-Encoding: gzip

HTTP/2 200
Content-Type: text/css
Content-Encoding: gzip

Limit cause and implement correction

Targeted limitation of the cause

Open the network area of the browser developer tools, deactivate the browser cache and reload the page. For a larger text resource, check content encoding as well as the transferred and unpacked size. If the coding is missing, compare Server and CDN. Already compressed images should not serve as evidence of a lack of text compression.

Change and follow-up audit

Enable compression for appropriate MIME types or configure the delivery of existing GZIP/Brotli files. Match file extension, content type, and content encoding; a mislabeled response body can make the stylesheet or script unreadable.

Then test both a browser with Brotli support and a retrieval without this support. Both must receive the same content. In addition, check that no outdated compressed variant is shipped after a change of the source text.

What makes you recognize a suitable correction

After the change, the negotiated response shows gzip or br; a call without support still receives readable CSS. Compare transferred and unpacked sizes separately.

Classification and boundaries

When is this indication not a clear error?

Already compressed image formats do not require the same text compression. Very small answers are not automatically a relevant bottleneck.

Further documentation

MDN: Content encoding

GZIP or Brotli compression missing after CMS and cause

Many audit messages can be resolved faster if they are grouped by system, page type and technical cause. CMS indentations are only linked where GZIP or Brotli compression lacks a clearly separate cause or fixed route in the respective system.

For this error, there is currently no own CMS deepening, because the correction is usually not sufficiently system-specific. Take advantage of the general causes and checks on this page.

Frequent causes of this error

JavaScript and performance budgetToo much JavaScript, blocking resources or client-side rendering worsen crawlability and core web vitals. Cache and CDN RulesCaching, CDN, edge rules or minification deliver old, blocked or technically modified pages. Media and image processesImage sizes, alt texts, lazy loading or media URLs are not maintained consistently or technically delivered incorrectly. Theme and page builder outputVisual builders, theme snippets, or design components generate HTML that is incomplete or contradictory to search engines.

Related SEO Errors

HTTP/2 is missingModern protocols improve parallel transmission and technical basis Cache control is missingClean caching rules reduce loading time and server load Image files too largeUnoptimized images slow down loading times and core-web hospitals Images without dimensionsMissing image dimensions can cause layout shifts

Appropriate Seitenreport checks

This error should not be checked in isolation. The following tools and clusters help to narrow down the cause faster and to cleanly prioritize the affected URL groups.

Image SEO CheckerCheck images, alt texts, lazy loading and file sizes.Open the check -> Performance toolsControl core web hospitals and load time signals.Open the check -> Accessibility toolsCheck alt texts, contrast, forms and usability.Open the check ->