AI-powered
A website speed test that loads a page in our own browser on a phone and a desktop, and shows what makes it slow.
AvailableReady to use.
Open the tool| Measure | Phone | Desktop |
|---|---|---|
| LCP | 3.9 s | 1.6 s |
| TBT | 420 ms | 60 ms |
| CLS | 0.02 | 0.01 |
| Page weight | 2.8 MB | 2.8 MB |
AI turns the measurements into a short fix list. The numbers come from our own browser, not from AI.
A phone sized browser with a slower processor loads the page.
The same page loads on a desktop browser.
Paint times, blocking time, layout shifts and every file are recorded.
What to fix first, with the files behind each number.
A website speed test loads a page the way a visitor's browser does and measures how long it takes to show, respond and settle. Ours loads the page in our own browser twice: once as a phone with a slower processor and once as a desktop.
The results are lab numbers: the same page, the same conditions, every time. That makes them good for finding causes and checking fixes. Real visitors on real networks can see different numbers.
LCP is when the largest piece of content appears. FCP is when anything appears at all. TBT is how long scripts block taps and clicks. CLS is how much the layout jumps while loading. TTFB is how long the server takes to answer.
Next to the numbers you see the page weight by file type, the heaviest files and the files that hold back the first view.
Large images that are bigger than the space they fill, too many scripts loaded before the content, web fonts that block text, and a slow server reply are the most common causes.
Fix the biggest file first, then delay scripts that are not needed for the first view. Test again to confirm the change helped.
Most visits come from phones, and phones have slower processors than laptops. A page that feels fast on a desktop can feel slow on a phone, so the phone result usually matters most.
No. They are lab numbers from our own browser. Google's real user data can differ.
The phone test uses a slower processor and a smaller screen, like many real phones.
Only the measurements and screenshots of the result.
No. Only public pages can be tested.