loading.no-compression
The HTML is sent uncompressed although the request accepted gzip, so every visitor and crawler downloads several times more bytes than needed.
What to change
Turn on gzip or Brotli compression for text/html (and CSS, JavaScript, JSON, SVG) in the web server, CDN or hosting settings: gzip on in nginx, mod_deflate in Apache, compression() middleware in Express.
The documentation on developer.chrome.comA finding of this rule on a page carries the exact edits for that page: the markup it quotes, and what to write instead.
When it runs
Runs on every SEO audit: of a page, a crawl, a build directory or HTML. A warning is a problem that costs a page ranking, clicks or citations. Each finding takes 5 points off the page's score.
The severity here is the rule's usual one: a finding can be raised or lowered when the page gives a reason.
Run it, or skip it
Check a page for this rule alone, after a fix for instance:
npx @rivi-software/agentic-seo-check audit https://example.com --rule loading.no-compressionOr from an assistant, with the MCP tool seo_audit_page:
{
"url": "https://example.com",
"rules": [
"loading.no-compression"
]
}To leave it out of an audit, pass --disable loading.no-compression on the command, or disableRules: ["loading.no-compression"] to a tool.
More in Performance
All 17 rules- Info
loading.render-blocking-scriptScripts in <head> load without async, defer or type="module", so the browser stops building the page until each one has downloaded and run. - Warning
perf.field-lcp-poorOn phones, real visits wait more than 4,000 ms for the largest element of the first screen at the 75th percentile: Largest Contentful Paint (LCP) in the Chrome UX Report's last 28 days, for the page's URL or, when it has too few visits, its origin. Google rates it poor. - Warning
perf.field-inp-poorOn phones, real visits wait more than 500 ms for the page to answer a tap or a key at the 75th percentile: Interaction to Next Paint (INP) in the Chrome UX Report's last 28 days, for the page's URL or, when it has too few visits, its origin. Google rates it poor. - Warning
perf.field-cls-poorOn phones, the layout of real visits shifts by more than 0.25 at the 75th percentile: Cumulative Layout Shift (CLS) in the Chrome UX Report's last 28 days, for the page's URL or, when it has too few visits, its origin. Google rates it poor. - Info
perf.field-lcp-needs-improvementOn phones, real visits wait more than 2,500 ms for the largest element of the first screen at the 75th percentile: Largest Contentful Paint (LCP) in the Chrome UX Report's last 28 days, for the page's URL or, when it has too few visits, its origin. Google rates it as needing improvement. - Info
perf.field-inp-needs-improvementOn phones, real visits wait more than 200 ms for the page to answer a tap or a key at the 75th percentile: Interaction to Next Paint (INP) in the Chrome UX Report's last 28 days, for the page's URL or, when it has too few visits, its origin. Google rates it as needing improvement. - Info
perf.field-cls-needs-improvementOn phones, the layout of real visits shifts by more than 0.10 at the 75th percentile: Cumulative Layout Shift (CLS) in the Chrome UX Report's last 28 days, for the page's URL or, when it has too few visits, its origin. Google rates it as needing improvement. - Warning
perf.lcp-slowLargest Contentful Paint above 2.5 s (poor above 4 s). Lab measurement from Lighthouse.