Does your page keep visitors waiting?
Enter your site's address. We load it on a simulated phone, on slow 4G, three times, and tell you what weighs: images, requests, cache, scripts.
The same page, two phones, the same network. The only difference: on the right, three images were recompressed and one word added to a tag. Watch who gets to read first.
The same page, loaded twice side by side. On the right, three recompressed images and one word in a tag. An hour's work.
1.3 seconds. On the right, the text is there, the visitor is reading.
On the left, still blank. Half the visitors are already gone.
5.4 seconds. The left page finally arrives, in front of nobody.
Four times faster, with identical content.
Nothing changed in the site's code. Three images and one word.
What divides the time by four takes three images and one word in a tag.
On a desktop, at the office, on fiber, you'll never see this wait. Your visitors will.
Weighttransferred
Imagesoversized
Requestsin total
Compressionbrotli, gzip
Cacheone day minimum
HTTP/2or HTTP/3
Scriptsrender-blocking
Fontslightweight
Third partiesshare of weight
Serverfirst byteWeighttransferredImagesoversizedRequestsin totalCompressionbrotli, gzipCacheone day minimumHTTP/2or HTTP/3Scriptsrender-blockingFontslightweightThird partiesshare of weightServerfirst byteTen structural checks, the same from Paris to Tokyo. Load times are shown as references, with their method: they don't enter the score.
Why not a simple stopwatch?
Because a stopwatch depends on everything: distance to the server, network, device, time of day. Two runs on the same site differ by 15%. What the page weighs, the request count, oversized images, caching and compression are the same from Paris to Tokyo, and they're what causes slowness. The score rests on those.
What are the displayed times worth?
They're reference points, not the score. They're measured in a simulated mobile browser, on a slow 4G network with a throttled CPU, from France, and the median of three runs is shown. The only time that enters the score is the server's, the first byte, because it depends on neither the device nor the rendering.
Why “from France”?
Because that's the viewpoint that matters for a site whose customers are there. A server on the other side of the world shows in the first byte, and that's information, not bias.
What does the score measure?
Ten checks in four categories, out of 100. Weight (total, images, requests), delivery (compression, cache, protocol), rendering (blocking scripts, fonts, third-party share) and the server. A check with nothing to examine, a page without web fonts for instance, leaves the calculation.
Who fixes this, and how fast?
Images are recompressed in an hour with the named list. Cache and compression are a few lines at your host. Blocking scripts need a “defer”. Nothing here requires rebuilding the site.
Test of example.com
0,0 sYour score is building.
Each category adds the points it earns, and shows the ones you're missing.