Up or Down Checker

Check if a site or server is online — HTTP status, response time, IP and server headers.

What Does the Up or Down Checker Verify?

The tool makes an HTTP(S) request to the domain or URL you enter and checks whether the server responds. The check is performed from our server, so if the result is "Online", the site is working for everyone — not just for you or a specific provider.

Online vs Offline — What Does It Mean?

Online (✅)

The server responded to the request within the time limit (15 seconds). This means the web server is running, DNS resolves correctly, and the connection is not being blocked. Even a 404 or 403 is considered "Online" — the server is alive, the specific page simply does not exist or access is forbidden.

Offline (❌)

The server did not respond. Possible causes: the server is down, DNS is not resolving, a connection timeout occurred, or a firewall is blocking external connections.

What Do the Fields Mean?

HTTP Status

The status code returned by the server for the request. The most common ones:

200 OK — The page loaded successfully
301 / 302 — Redirect to another address (the tool follows up to 5 redirects)
403 Forbidden — The server responds but denies access (e.g. CloudFlare bot protection)
404 Not Found — The page was not found, but the server is working
500 / 503 — Internal server error — possible outage

Response Time

The time it took the server to respond, in milliseconds (ms). Generally: <300ms is excellent, 300–800ms is good, >800ms is slow, >2000ms is very slow.

IP Address

The IP used for the connection (the final resolved IP after any CDN or load balancer). You can click "IP WHOIS →" for detailed information.

Server

The value of the Server HTTP header returned by the web server (e.g. nginx, Apache, cloudflare). Not all servers include this header.

Frequently Asked Questions

The tool says Online but I can't open the site?

This usually happens due to a local DNS cache. Try opening the site from a different network (e.g. mobile data) or use the Έλεγχος DNS to check the DNS records. Also try flushing your local DNS cache (ipconfig /flushdns on Windows).

The tool says Offline but the site opens normally?

Your server may be blocking requests from our IP address (firewall, geo-restriction). In this case the site works for visitors but not for our check. Try the Redirect Checker which makes a full request.

Why do I see 403 when the site opens normally in the browser?

Many sites (using Cloudflare, Akamai, or other WAFs) block requests from automated agents/bots without a browser session. The server is genuinely Online — the 403 applies exclusively to the checker's request.

How often is the result refreshed?

Results are cached for 60 seconds. For real-time monitoring with alerts, use the Domain Monitor.