522
Connection Timed Out
A Cloudflare-specific status code meaning Cloudflare could not establish a TCP connection to the origin server within 15 seconds. The origin server is unreachable — it is either down, firewalled, or overloaded.
What does HTTP 522 mean?
A Cloudflare-specific status code meaning Cloudflare could not establish a TCP connection to the origin server within 15 seconds. The origin server is unreachable — it is either down, firewalled, or overloaded.
Common causes
- 1
The origin server is down or not listening on the expected port. The server process has crashed or was never started.
- 2
A firewall, security group, or iptables rule is blocking Cloudflare's IP ranges from reaching the origin server.
- 3
The origin server is overloaded and its TCP connection backlog is full, causing new connections to be dropped.
How to fix it
- 1
Verify the origin server is running and listening on the correct port. Check with ss -tlnp or netstat to confirm.
- 2
Whitelist all Cloudflare IP ranges in your firewall. Cloudflare publishes its IP list at cloudflare.com/ips. If you restrict access to Cloudflare IPs only, ensure the list is up to date.
- 3
If the server is overloaded, scale resources or reduce traffic. Check for connection limits in your server config (e.g., worker_connections in nginx).
Monitor for HTTP 522 errors
A 522 means your server is completely unreachable from Cloudflare — this is a full outage for all users behind the CDN. Uptrack alerts you within 30 seconds so you can restore connectivity fast.
Catch HTTP errors before your users do
20 monitors free — 10 at 30s, 10 at 1min. No credit card required.
Start Monitoring Free