Speed
Nothing needless blocks first paint
performance.render-blocking-resources
Why this matters
The browser will not draw a single pixel until certain stylesheets and scripts have finished downloading. On a phone that is dead time the visitor spends looking at nothing. It is worse when one of those files is pulled in by an @import inside another stylesheet, because it cannot even start downloading until the first has arrived.
Who fixes it
A developer
Roughly how long
Varies
Care needed
Test before and after
How to fix it
Replace any CSS `@import` with a `<link>` in the head so the browser can fetch it in parallel — or better, self-host and bundle it. Inline the small amount of CSS needed for the top of the page and load the rest asynchronously; add `defer` to scripts that do not need to run before the page is drawn. If the blocking resource is a webfont and the site is built with Next.js, `next/font` self-hosts the files and removes the external request entirely — and generates a metric-matched fallback, which also removes the layout shift the swap would otherwise cause.
How we score it
Failing this check takes up to 12 points off your speed score. It is a fact about your site rather than a measurement, so it reads the same on every scan until you change something.
Does your site pass this one?
This check runs on every scan, along with the other 106. Free, no account, and you see the evidence for each result.
Check my siteOther speed checks
- Every page gets the files it asks forA file that is missing on one template is missing on every page built from it, which is usually hundreds of pages rather than one. It is also the hardest kind to notice from the inside: a browser that has an older copy of the file will carry on showing it long after the file itself has gone, so the site looks correct to whoever built it and broken to everybody arriving fresh.
- Every page responds promptlyWhen one part of a site responds noticeably slower than the rest, it usually points at one specific thing rather than at the hosting in general — a heavy search query, an unindexed database lookup, or a page rebuilding something on every request. That makes it one of the more fixable speed problems, because there is a single cause to find.
- Everything the page asks for loadsYour page requests these and gets nothing back. Depending on what they are, that means a missing image, a stylesheet that never applies, or a script that never runs — and the page may look fine to you if your browser has an older copy cached.
- First visit after a quiet spell is not slowSome hosting puts a site to sleep when nothing has visited for a while, and the next request has to wake it. Once warm the site is fine, which is why this is easy to miss — the person testing it has usually just loaded the page. The people who get the slow version are the ones arriving overnight, and Google when it crawls at an odd hour.
- Google has enough visitor data to report on your siteGoogle publishes real-visitor speed figures for a site only once enough Chrome users have been there to make the numbers meaningful and anonymous. Below that threshold there is nothing to publish, which is the ordinary situation for a small business site and says nothing about how well the site is built. It does mean every speed figure in a report like this one is a simulation rather than a record of what happened to anybody.
- Images reserve their space before loadingThe browser cannot tell how tall these images will be until they have downloaded, so it draws the page without them and then pushes everything down when they arrive. That is the jump people experience as a page moving under their thumb.