Measure how fast a site responds from Europe and the US, with a phase-by-phase breakdown including time to first byte (TTFB).
The Response Time Checker measures how quickly a website responds — not just whether it's up, but how fast. It reports a total time and a speed band, plus a per-phase breakdown so you can see where the time goes: DNS lookup, TCP connect, TLS handshake, time to first byte (TTFB), and content download.
Use it to tell a slow backend (high TTFB — the server is thinking) from a slow transfer (large page, slow network), and to compare speed between Europe and the US.
| Result | What it means |
|---|---|
| Fast | Responded in under ~0.5 seconds. Excellent. |
| OK | Responded in roughly 0.5–1 second. Fine for most visitors. |
| Slow | Took around 1–3 seconds. Noticeable; worth investigating. |
| Very slow | Took 3 seconds or more. Visitors will feel this and may leave. |
| Blocked | A bot-protection challenge intercepted the request, so the timing isn't a true reflection of the site's speed (shown in amber, not as a failure). |
| Failed | No usable response — the site timed out, errored (5xx) or couldn't be reached. See the reason shown. |
| Message | What it means |
|---|---|
| Timed out | No response within the time limit — the server is very slow or unreachable from that region. |
| Domain could not be resolved | DNS lookup failed. Check the spelling, or the domain's DNS may be down. |
| SSL error | The secure (TLS) connection couldn't be completed — often a certificate problem. |
| Too many redirects | The URL redirected in a loop without reaching a final page. |
| Connection refused | The server rejected the connection — it may be down. |
| Server error (5xx) | Reached the server, but it returned a 5xx error. Up, but failing. |
| Client error (4xx) | The server returned a 4xx such as 404 — the address may be wrong. |
| Blocked (401/403) | The page needs authorisation or a firewall blocked the checker. |
| Blocked by bot protection | A challenge page (e.g. Cloudflare) intercepted the request; the real site is probably fine for visitors. |
| Region much slower (warning) | One region was at least twice as slow (and 400ms+ slower) than the other — a sign of distance from your server or no CDN. |
| HTTPS→HTTP downgrade (warning) | A redirect stepped down from a secure https address to an insecure http one — a misconfiguration worth fixing. |
These tools are one-off checks. A Monitrova account monitors your sites continuously and emails you the moment something breaks.