Frequently asked questions

When you press Check, our server visits the address the same way a web browser does — from outside your own internet connection. If the site's server answers, it's up. It's down only when there's a real failure: the domain doesn't resolve, the connection is refused or times out, the secure (HTTPS) connection is broken, or the server returns a 5xx server error. Failures are re-tried (including the www. version of the address) before we report them.

Then the problem is most likely between you and the site, not the site itself. Try, in order: reload the page, open it in a private/incognito window, switch from Wi-Fi to mobile data, turn off any VPN or ad blocker, restart your router, and clear your DNS cache. Our guide Is it down for everyone or just me? walks through each step.

Many large websites use bot protection (for example Cloudflare or Akamai) or answer automated visitors differently from people. They may reply to a checker with 403 Forbidden, 429 Too Many Requests or even 404 Not Found, while the page loads normally in a browser. A reply of any kind proves the server is online, so we report it as up and explain the code — rather than giving you a false "down".

2xx means the page loaded normally. 3xx is a redirect, which we follow. 4xx means the server is working but refused or couldn't find what was asked for. 5xx means the server itself is failing — that's a genuine outage. Codes 520–530 come from Cloudflare when it can't reach a site's own server. See HTTP status codes explained for the full list.

It's possible, though we work hard to avoid it. A site might block traffic from data-centre networks or from certain countries, or have a fault that only affects some regions. If a result looks wrong, press Check again, and please let us know — reports like yours help us improve the checker.

Every check runs live, at the moment you ask. To avoid flooding a website that many people are checking at once, checks of the same address within about 20 seconds share one result. The time of each check is shown next to it.

Yes. It shows the domain name (for example example.com), its status and when it was checked — never the full link you typed, and never who checked it. Addresses that don't exist are left off the list. Please don't use the checker for private or internal links.

Yes — paste the full address, such as https://example.com/shop. Standard web ports (80, 443, 8080 and 8443) are supported. Only public websites can be checked; private and internal network addresses are blocked for security.

It's free and needs no account. To keep it fast for everyone there's a fair-use limit of 20 checks per minute per visitor.

Not at the moment — CheckIfSiteDown is an on-demand checker. For round-the-clock monitoring with email or SMS alerts, use a dedicated uptime-monitoring service. Our guide on false "down" results explains what to look for in one.