Is my site down?

This checks a site from outside your network, and then checks it again in a way its CDN cannot answer from cache. The second part matters: a CDN can keep serving a stored copy of your site long after the server behind it has stopped answering.

What does this check actually do?

Two requests to the address you enter, from this site's own edge network. The first is the URL exactly as given, the way any visitor would load it. The second carries an extra throwaway query parameter, which makes it a page no cache has stored - so it can only be answered by the server itself. Both requests follow up to three redirects, time out after eight seconds, and read nothing but the status code and a handful of response headers. The verdict comes from comparing them.

Why check twice? Because a CDN can hide an outage.

If your site sits behind Cloudflare, CloudFront, Fastly, or any other CDN, most requests are answered by a copy stored at the edge, not by your server. That is the point of a CDN - and it is also a blind spot: when your server dies, the edge keeps answering with the copy it has. A plain uptime check sees a 200 and reports everything fine, your homepage stays up, and meanwhile every login, checkout, search, and form on the site is failing, because those cannot be served from cache. The industry name for the general idea is a false green: the dashboard says up, the users say down.

The cache-busted request is how this page sees through that. A healthy origin answers it. A dead origin behind a warm cache cannot - and that combination, first request fine, unstorable request failing, is exactly the outage a plain check misses.

What do the results mean?

Up means both requests got answers: your server is reachable and responding, cache or no cache. Cached page over a dead origin means the plain request was served from a cache and the unstorable one got no answer: visitors are seeing yesterday's site while the server is not answering. Down means not even the cache answered, and the detail line names the failure: a status code, a timeout, or a connection that never opened. Status codes 520 through 524 are a special case worth knowing: they are Cloudflare saying its edge is fine but your server behind it is not reachable.

The site is up here but down for me. Which is wrong?

Possibly neither. This page checks from one place: whichever of this site's edge locations answered you (shown under the verdict). Your browser sits on a different network, with different DNS answers and a different route. A site really can be up from one network and down from another - a regional CDN failure, a broken IPv6 record your network prefers, or an ISP-level block all produce exactly that split. We wrote up how to tell those apart inup for me, down for others.

That is also this tool's honest limitation. One check from one vantage point is a snapshot, not monitoring. YoPingMe watches your site from two regions you pick, free - chosen from five probe locations on three continents - and pages you only when both agree it is down, which is how you avoid both missed outages and false alarms.

What this page does with the URL you enter

It is fetched twice from the edge, the verdict is computed, and that is the end of it: the URL is not logged by this page, stored, or added to any list. The checker sends an honest user agent naming this page, reads no page content, and refuses to probe private addresses - if it is not reachable from the public internet, it has no public uptime to check.