Is my site down?

One check, right now, from a real datacentre in the region you pick. No account, no card, nothing stored — and the same measurement the paid product makes every minute.

What this tells you, and what it does not

A single check is a snapshot. It answers "is it responding right now, and how fast" — which is exactly the question you have when something feels wrong, and almost never the question you have afterwards.

What a snapshot cannot tell you is whether it was down at four this morning, whether it has been getting slower for a fortnight, or whether it fails one time in twenty. Those need someone checking on a schedule and keeping the history — which is the whole of the paid product, and free for three URLs.

Why the response time may surprise you

Distance is most of it. The same page can answer in 24 ms from Stockholm and 250 ms from Taipei, and none of that difference is your server. Check from the region your visitors are actually in.

Why a download time of zero is usually correct

The clock in this runtime only advances after I/O, so a response body that is already buffered when the headers arrive downloads in unmeasurable time. Zero means "too small to measure", not "broken" — and it is most common on error pages, which are tiny.

If it says 403 and your browser says otherwise