FREE WEBSITE SPEED TEST
Website speed test: how fast does your site load?
Enter your URL to run a website speed test on mobile. You see the Core Web Vitals that Google measures, and where your page loses time.
WHAT THE TEST MEASURES
Core Web Vitals
This speed test loads your page the way a phone does and measures how long it takes before the page is on screen and responds. Of the three Core Web Vitals, the test measures LCP and CLS directly. For the third, INP, it looks at TBT.
The test simulates an average phone on slow 4G. Visitors with a faster phone or Wi-Fi often experience your site as faster than this score shows. If your page scores well on this strict measurement, it also loads quickly on a slow connection.
- Speed score
Overall score based on all the measurements
- Main content on screen (LCP)
How fast the largest element appears on screen
- First content on screen (FCP)
When something first appears on screen
- Response to taps (TBT)
How long the page doesn't respond to a tap or click
- Layout stability (CLS)
How much elements shift around while the page loads
- Page size
Total size of the page in KB/MB
LAB AND REAL WORLD
The test is a lab measurement
How the lab test works
- A measurement on simulated slow 4G
- An average phone
- The same conditions every time
- Useful for tracking down technical problems
What the test doesn't measure
- Measurements from your real visitors
- Differences by location and network
- How visitors experience the speed
- The effect of caching on a second visit
Besides LCP and CLS, the test measures FCP, TBT and an overall speed score. If your site gets enough traffic, Google also measures speed with real visitors. You'll find those numbers in Google Search Console, under Core Web Vitals.
YOUR SCORE
What does your score mean?
A score of 90+ is good. Between 50 and 89, there's room to speed up. Under 50, something is seriously in the way, usually one of the four causes further down this page.
Compare your score with others in your industry
A simple business site can reach 90 or higher, even on this strict measurement. A large online store or web app naturally scores lower, because a lot more code loads along with it. So compare your score with competitors in the same industry.
Speed is one of the signals Google looks at for SEO. Your content, your backlinks and how visitors behave on your site count too. So a perfect score won't automatically move you up in Google, but your visitors do notice a slow site right away.
GOOGLE'S THRESHOLDS
What is a good load time?
For a good load time, Google uses three thresholds, the Core Web Vitals. Stay below them and you're fine. Go above them, and you see right away which of the three needs attention.
The load time of the largest element on your screen, often the hero image or the headline. That's how long it takes before your visitor feels the page is there.
How fast your page responds when someone clicks or taps something. If that takes too long, the site feels slow, even when everything is already on screen.
How much the page jumps around while it loads. A button that moves just as you want to click it: that's a high CLS.
INP can only be measured when real visitors tap and click on your page. This test runs without visitors, so it looks at TBT, the time the page doesn't respond. TBT is a good predictor: if it's high, your INP with real visitors is usually too slow as well.
CAUSES
Why is your website slow?
It usually comes down to a few familiar causes. These four are the ones I run into most often, and under each cause you'll find where to look for the fix.
Images that are too heavy
Photos of a few megabytes are the biggest slowdown, so that's usually where there's the most to gain.
Too many scripts
Every plugin, tracker and widget loads code that blocks the page before it's ready.
Slow hosting
On cheap, overcrowded servers it simply takes longer for the first byte to arrive.
No caching
Without caching, your site rebuilds every page on every visit, even when nothing has changed.
If your site runs on WordPress, the right technical optimization often gets you a lot more speed.
OTHER FREE TOOLS
Keep checking
Every tool is free and works without an account.
Website checker
One score for the SEO, speed, security, technical setup and accessibility of a page.
Keyword rank checker
Up to 10 search terms that fit what you offer, and whether you are already on page 1 of Google.
SEO checker
Whether Google can read your page properly, and why each point matters.
Keyword research tool
How often people search for your keywords, up to 10 at once, with the trend over a year.
Accessibility checker
Whether your page works for people with a disability.
AI checker
Whether a Dutch text was written by a person or by AI.
FREQUENTLY ASKED QUESTIONS
FAQ about website speed
VIZIBLY QUICK SCAN
Website too slow?
I build my websites for speed from the first line of code, so they load quickly on a phone too. Request the free Quick Scan, and I'll look at your site and your market and point out where your site is slow and where you're missing out on clients.
Prefer to talk first? Schedule a call.
Request the free Quick Scan
Two short steps. It takes less than a minute.