A page won't load. Before you restart the router, message support or wake up a developer, answer one question: is the website down for everyone, or just for you? Those two answers lead to completely different fixes, and you can tell them apart in under two minutes.
Here are seven checks, in the order we'd run them, plus what each result means.
The quick answer
Open the site from a different network - ideally from a server somewhere else in the world. The fastest way is our free website checker: it requests the page from Upmonora's servers and shows the HTTP status, response time and SSL status. If it loads there but not for you, the website is fine and the problem is on your side. If it fails there too, the site really is down.
1. Read the error the browser shows
The error message already tells you roughly where things broke:
| What you see | What it usually means | Whose problem |
|---|---|---|
| DNS_PROBE_FINISHED_NXDOMAIN / "server IP address could not be found" | The domain name did not resolve | Often yours (DNS resolver), sometimes the site's (expired domain, broken DNS) |
| ERR_CONNECTION_REFUSED | Server reachable but nothing is listening on the port | The site's |
| ERR_CONNECTION_TIMED_OUT | No reply at all - server down, or a firewall is dropping traffic | Either |
| 502 Bad Gateway | A proxy or CDN could not get a valid answer from the app server | The site's - see our 502 guide |
| 503 Service Unavailable | The server is overloaded or in maintenance | The site's |
| NET::ERR_CERT_DATE_INVALID | The SSL certificate has expired | The site's - see SSL expiry outages |
A 5xx status code is the clearest signal: the server answered, which means your connection works and the problem is on the website's end.
2. Try two or three other websites
If nothing loads, the issue is your connection, not the site. Restart the router, check that you're actually connected to Wi-Fi, and look for a captive portal (hotel and office networks often need a login page first).
3. Switch networks
Turn off Wi-Fi on your phone and open the site on mobile data. If it works on mobile data but not on your office or home network, something between you and the site is blocking it: the router, a corporate firewall, a parental filter, a VPN or your ISP's DNS.
4. Check from outside with an online tool
An external check removes your whole setup from the equation. Paste the URL into the Upmonora website checker and look at three things:
- Status code. 200 means the page loaded. 3xx is a redirect (normal). 4xx and 5xx are errors.
- Response time. Over 3-5 seconds is slow enough that people give up, even though the site is technically "up".
- SSL. An expired or mismatched certificate makes browsers block the page even when the server works.
5. Rule out DNS
DNS turns a name like example.com into an IP address. If your resolver has a stale or broken record, the site looks down to you and fine to everyone else. Look the name up from the command line:
nslookup example.com # or, more detail: dig example.com +short dig @1.1.1.1 example.com +short # ask Cloudflare's resolver directly
If your default resolver returns nothing (or an old IP) but 1.1.1.1 or 8.8.8.8 returns an address, flush your DNS cache or switch resolvers:
# macOS sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder # Windows ipconfig /flushdns
6. Ask the server directly with curl
curl shows exactly what the server returns, without browser caches or extensions getting in the way:
curl -sS -o /dev/null -w "HTTP %{http_code} in %{time_total}s\n" https://example.com
HTTP 200 in 0.41s means the site is up and reasonably fast. A timeout, Could not resolve host or a 5xx code tells you where the failure is. Add -v to see the TLS handshake and headers.
7. Clear the browser out of the way
If the site works in curl and in an external checker but not in your browser, open a private window. If that works, a cached redirect, a bad cookie or an extension (ad blockers are common culprits) is to blame. Clear site data for that domain only - there's no need to wipe everything.
If it's your website that's down
When the external check fails too, work from the outside in:
- Domain and DNS: has the domain expired? Did someone change nameservers?
- Certificate: has the SSL certificate expired?
- CDN or proxy: a 502, 504 or 52x error page from your CDN means it can't reach your origin server.
- Server: is the web server process running? Is the disk full? Is the database up?
- Recent changes: most outages follow a deploy, a plugin update or a config change. Roll back first, investigate second.
Running WordPress? Our WordPress recovery checklist walks through each step.
Stop checking manually
Every check above has one weakness: it only tells you about the moment you looked. Most people find out about their own outages from a customer, hours later. Uptime monitoring runs the same external check every 30 seconds to 5 minutes, from outside your network, and alerts you by email, Slack, Microsoft Teams or webhook when it fails.
To avoid false alarms, Upmonora only opens an incident after a set number of consecutive failures, so a single dropped request never pages you. Here's why that matters. The free plan covers 5 monitors with SSL checks and a status page included.
Frequently asked questions
How do I know if a website is down for everyone?
Check it from a different network and location. An online checker such as the free Upmonora website checker requests the page from our servers, so if it loads there but not for you, the problem is on your side (DNS, network, browser or firewall).
Why does a website work on my phone but not my computer?
Usually because the phone is on mobile data and the computer is on Wi-Fi. That points to your router, DNS resolver, VPN or a local firewall rather than the website itself. Try flushing DNS or switching the computer to the phone hotspot.
What does "This site can't be reached" mean?
The browser could not open a connection at all. Common causes are a DNS lookup failure, the server refusing connections, or a network block. If the error says DNS_PROBE_FINISHED_NXDOMAIN, the domain name could not be resolved.
How often should I check if my own website is down?
Automatically, every 1 to 5 minutes. Manual checks only tell you about the moment you look. An uptime monitor checks around the clock and alerts you as soon as a real outage starts.