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Error 522

Error 522: connection timed out

Error 522 occurs when Cloudflare times out contacting the origin web server.

Common causes

Two different timeouts cause HTTP error 522 depending on when they occur between Cloudflare and the origin web server:

  • Before a connection is established, the origin web server does not return a SYN+ACK to Cloudflare within 19 seconds of Cloudflare sending a SYN.
  • After a connection is established, the origin web server does not acknowledge (ACK) Cloudflare's resource request within 90 seconds.

Resolution

  • Contact your hosting provider and share the necessary error details to assist in troubleshooting these common causes:

    • Cloudflare IP addresses ↗ are rate limited or blocked in .htaccess, iptables, or firewalls. Confirm your hosting provider allows Cloudflare IP addresses (most common cause).
    • An overloaded or offline origin web server drops incoming requests.
    • Keepalives ↗ are disabled at the origin web server.
    • The origin IP address in your Cloudflare DNS app does not match the IP address currently provisioned to your origin web server by your hosting provider.
    • Packets were dropped at your origin web server.

  • If you are using Cloudflare Pages, verify that you have a custom domain set up and that your CNAME record is pointed to your custom Pages domain.

  • If you are using Workers with a Custom Domain, performing a fetch to its own hostname will cause a 522 error. Consider using a Route, targeting another hostname, or enabling the global_fetch_strictly_public compatibility flag instead.

  • If none of the above leads to a resolution, request the following information from your hosting provider or site administrator before contacting Cloudflare support:

    • An MTR or traceroute from your origin web server to a Cloudflare IP address ↗ that most commonly connected to your origin web server before the issue occurred. Identify a connecting Cloudflare IP recorded in the origin web server logs.
    • Details from the hosting provider's investigation, such as pertinent logs or conversations with the hosting provider.