How to Check If a Website Is Online or Down

A page won't load, or a customer says your site isn't working. The first question is always the same: is the website online, or is it down? And right behind it: is it down for everyone, or just for me? This guide shows seven ways to check if a website is online, from a ten-second check to command-line tools, and then explains how to narrow a real outage down to its cause.

What "online" actually means

A website is only truly online when visitors can load a working page. That requires every step to succeed: the domain name resolves in DNS, the server accepts a connection, the SSL certificate is valid for HTTPS, and the application returns a successful response. A failure at any step makes the site unusable, even if the server itself is running.

In practice there are three outcomes:

• Online: the page loads, with an HTTP status code in the 2xx range (or a 3xx redirect that leads to one).
• Online but broken: the server answers, but with an error such as 500 Internal Server Error or 503 Service Unavailable.
• Offline: no usable answer at all, because of a DNS failure, timeout, SSL error or refused connection.

Keep these in mind, because some methods below can only detect one of them.

Swipe sideways to see the whole diagram

7 ways to check if a website is online

1. Use an online website status checker

The fastest and most reliable method for most people. An online checker requests the site from its own server, outside your network, so it isn't affected by your connection, browser cache or local DNS. Our free website status checker shows the result, the HTTP status code, the response time, the final URL after redirects and the reason for any failure. No account is needed.

Detects: online, online but broken, and offline, including the cause.

2. Try another device or network

Open the site on your phone using mobile data instead of Wi-Fi, or ask someone in another location to try. If it works there but not on your computer, the problem is on your side.

Detects: whether the issue is local. It doesn't tell you why the site fails.

3. Ping the server

From a terminal or command prompt:

ping example.com

Ping sends small network packets (ICMP) and reports whether the host answers. It's useful for checking basic network reachability, but it has two big limitations: many servers and firewalls block ping, so a website can be perfectly online while ping fails, and a server can answer ping while the website on it returns errors. Don't rely on ping alone to decide whether a website is online.

Detects: network reachability of the host only.

4. Request the page with curl

curl is installed on macOS, Linux and recent versions of Windows. Ask for the response headers only:

curl -I https://example.com/

The first line shows the HTTP status code, for example HTTP/2 200. A connection error, timeout or certificate error is printed instead if the site can't be reached. To follow redirects to the final page, add -L.

Detects: online, online but broken, and offline. Note that it runs from your own network.

5. Look up the DNS records

If the browser says the site "can't be reached" or the "server IP address could not be found", check whether the domain resolves:

nslookup example.com
dig example.com A +short

No answer means a DNS problem: the records are missing or wrong, the DNS provider has an issue, or the domain registration has expired. You can also use the free DNS lookup tool. Read more in How DNS Problems Can Make Your Website Unavailable.

Detects: DNS failures only.

6. Check the SSL certificate

If the browser shows "Your connection is not private" or a similar warning, the site may be online but blocked by a certificate problem. The SSL certificate checker shows whether the certificate is trusted, which names it covers and exactly when it expires.

Detects: certificate problems that make an online site unusable.

7. Check status pages and official channels

Large services publish status pages that report incidents. For your own website, check the status pages of your hosting provider, CDN and DNS provider: if they're having an incident, your site may be affected.

Detects: known, announced incidents only.

Comparison

Down for everyone or just you?

Combine an external check with what you see yourself:

• External check says online, but it fails for you: the problem is on your side.
• External check fails and it fails for you: the website has a real problem.
• External check fails but it works for you: the site probably blocks automated requests or traffic from data centres or certain countries.

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If the problem is on your side

1. Reload without the cache. Use a hard refresh (Ctrl+Shift+R on Windows and Linux, Cmd+Shift+R on macOS) or open a private window.
2. Disable browser extensions, especially ad blockers and privacy tools.
3. Try another browser or device on the same network.
4. Restart your router if several websites fail at once.
5. Flush your DNS cache. On Windows, run ipconfig /flushdns. On macOS, run sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder. This helps when a site recently moved to a new server.
6. Check VPNs, proxies and corporate firewalls, which may block certain sites.

Read the browser's error message

The exact wording of the error is a valuable clue about which step failed:

• "This site can't be reached" / "Server not found" / DNS_PROBE_FINISHED_NXDOMAIN: the domain name could not be resolved. A DNS problem.
• "Connection timed out" / ERR_CONNECTION_TIMED_OUT: the server's address is known but it doesn't answer. It may be offline, overloaded or behind a firewall.
• "Connection refused" / ERR_CONNECTION_REFUSED: the machine answered but nothing accepts web connections; the web server may have stopped.
• "Your connection is not private" / NET::ERR_CERT_DATE_INVALID: a certificate problem, often expiry.
• A page saying 500, 502, 503 or 504: the server is reachable but something behind it failed. See Understanding HTTP Status Codes.

Your own website is down: narrow down the cause

If the site is down for everyone and it's yours, work through the layers from the bottom up:

1. DNS: does the domain resolve to the right IP address? Has the domain registration expired?
2. Connectivity: does curl -I time out (server or network down, firewall) or get refused (web server not running)?
3. Certificate: is the SSL certificate valid and does it cover the domain?
4. Application: which status code does the server return? A 500 points to the application and its error logs; 502 or 504 to the application behind a proxy; 503 to overload or maintenance mode; a redirect loop to conflicting redirect rules. The HTTP status checker shows the full redirect chain.
5. Recent changes: deployments, plugin updates, DNS edits and expired payments cause a large share of outages. See What Causes Website Downtime?
6. Providers: check the status pages of your hosting, CDN and DNS providers.

If the site is online but slow rather than down, the website response time checker shows whether DNS, the connection, SSL or the server is taking the time.

Stop checking manually

Every method above tells you about one moment. If the website is yours, you want to know about the next outage before your visitors do, including at 3 a.m. That's what uptime monitoring automates: the same check, repeated every few minutes from outside your network, with an alert when the site goes down and another when it's back.

UptimeStats checks up to 5 websites every 5 minutes for free, classifies failures as DNS, timeout, SSL, connection or HTTP errors, confirms them with a second check before alerting, and keeps a history of every incident. New to the topic? Start with Website Monitoring: A Complete Beginner's Guide.

Quick checklist

• Run an external check with a website status checker.
• Compare with another device or network to see if the problem is yours.
• Don't trust ping alone; check the actual page and its HTTP status code.
• Read the exact browser error to identify the failing layer.
• For your own site, check DNS, connectivity, the certificate, the status code and recent changes.
• Set up monitoring so you hear about the next outage first.