Website Speed Test
Measure how fast a page loads from your browser — total load time, and TTFB where the server allows it — then get plain-language tips on what to fix.
Runs in your browser, from your connection. Cross-origin sites only expose detailed timing when they send a Timing-Allow-Origin header — otherwise you'll see total load time only. This is a real-world check, not a lab audit.
How this website speed test works
When you enter a URL, your browser requests that page and we time the whole journey with the high-resolution performance clock: from the moment the request leaves your device to the moment the full document body has arrived. Where the server permits it, we also read the Resource Timing API to pull out the Time to First Byte (TTFB) and the number of bytes transferred. Everything happens on your machine — there's no middle server, so the number reflects what a real visitor on your connection would experience.
Because the test is honest about its limits, it tells you when it can't read a metric instead of inventing one. For a full lab audit with Core Web Vitals, see our measurement method.
How to read your results
Two numbers tell most of the story. TTFB is how long the server took to start responding — high TTFB usually points at slow hosting, a database bottleneck, or a missing CDN. Total load adds the time to download the document; a large gap between the two means a heavy page or a slow link.
| TTFB | Verdict | Likely cause |
|---|---|---|
| < 200 ms | Excellent | Well-tuned hosting + CDN |
| 200–600 ms | Acceptable | Shared hosting or distant server |
| > 600 ms | Needs work | Slow backend, no caching, no CDN |
If TTFB is the weak point, a faster host or a content delivery network is usually the highest-impact fix. We may earn a commission from some links to hosting and CDN providers.
Frequently asked questions
- Why is my result different from PageSpeed Insights or Lighthouse?
- This test runs entirely in your browser, from your location and over your connection. Lab tools like Lighthouse run on a controlled server with a simulated network, and they also render the page to capture Core Web Vitals (LCP, CLS, INP). Use this tool for a quick, real-world feel; use a lab tool for a full audit.
- Why can't I see the TTFB for some sites?
- Detailed timing (TTFB, transfer size) comes from the Resource Timing API, which only exposes those numbers cross-origin when the server sends a Timing-Allow-Origin header. Most sites don't, so for those you'll see total load time only. That's a browser privacy rule, not a bug.
- What is a good load time?
- As a rule of thumb, a Time to First Byte under 200 ms is excellent and under 600 ms is acceptable. For the full page, aim to be interactive in under 2.5 seconds on a typical connection. Slower than that and visitors start to drop off.
- The test failed with a CORS or network error. What happened?
- Browsers block scripts from reading the response of another origin unless that server explicitly allows it. When that happens we can't measure the download reliably, so we report it honestly instead of guessing. Try a URL on your own domain, or use the server-side method linked below.
- Does this measure my internet speed or the website's speed?
- Both play a part. A slow result can come from the site's hosting and CDN, or from your own connection. To separate the two, run our connection speed test and the full Doctor diagnosis as well.
A slow page is a symptom, not a diagnosis
Load time alone won't tell you whether the bottleneck is the site's hosting or your own connection. Run the full Doctor check-up to see the whole picture — speed, latency, DNS and routing — and what to fix first.
Run a full diagnosis