The fastest check
- Go to downforeveryoneorjustme.com or isup.me
- Enter the domain
- If it says "It's not just you" — the site is down globally. Wait.
- If it says "It's just you" — the site is up. Your connection or local DNS is the problem.
Diagnosing "it's just you" — five causes
1. DNS cache
Your computer caches DNS lookups to avoid repeated lookups. An old cached IP can send you to a server that no longer exists or has moved.
Fix: flush your DNS cache.
- Windows:
ipconfig /flushdns - Mac:
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder - Chrome: navigate to
chrome://net-internals/#dns→ Clear host cache
2. Browser cache
A cached broken response or redirect can block the site. Open an incognito window and try the URL there. If it loads, the issue is browser cache — clear it with Ctrl+Shift+Delete.
3. ISP or DNS resolver
Your ISP's DNS resolver may have a stale or incorrect record. Try a different DNS:
- Change your DNS to Google (8.8.8.8) or Cloudflare (1.1.1.1) temporarily
- Or try the URL on your phone's mobile data (which uses a different DNS and network)
Check DNS records for the domain with the free DNS lookup tool to see if they resolve correctly.
4. Your firewall or security software
Antivirus, corporate firewalls, or parental controls can block specific domains or categories. Temporarily disabling security software for a test tells you if it's the cause.
5. Geographic restriction or CDN routing
Some sites restrict access by country (geo-blocking) or have CDN nodes that are down in specific regions. A site accessible in the US may be unavailable in Europe at the same time. A VPN can test whether it's a regional issue.
Diagnosing "it's down globally"
If the site is down for everyone, the causes are typically:
- Server outage: hosting provider issue, out of resources, or crashed server
- Expired SSL certificate: browsers block sites with expired certs even if the server is running — check with the SSL checker
- DNS misconfiguration: the domain's DNS records point to the wrong server or expired
- DDoS attack: the server is overwhelmed by malicious traffic
- Domain expiry: the domain registration lapsed
For site owners: quick health checks
If it is your own site that is down, check in this order:
- SSL certificate — is it valid and not expired?
- DNS records — does the A record point to the correct IP?
- Server status — is the hosting provider reporting an outage?
- HTTP status — does the server return a 200 or an error code?
HTTP status codes you might see
| Status | Meaning |
|---|---|
| 200 OK | Working normally |
| 301/302 | Redirect — may loop or point to wrong destination |
| 403 Forbidden | Server is up but blocking access (IP ban, auth required) |
| 404 Not Found | Server is up, URL doesn't exist |
| 500 Server Error | Server is up, application crashed |
| 502/503/504 | Server is overloaded or upstream is down |
Summary
Check downforeveryoneorjustme.comfirst. If it's just you: flush DNS cache, try incognito, try mobile data. If it's globally down: wait, check your hosting provider status page, verify SSL and DNS with the free tools. For site owners, check SSL first — expired certificates are one of the most common causes of "site is down" reports.