Cloudflare errors

Cloudflare sits between your visitors and your server. When it can't get a good answer from your server, it shows its own error page instead of the site. The problem is nearly always on the server behind Cloudflare, not at Cloudflare itself.

How to fix it

Look up the number on the error page. WP Moo sees the site again on its next check.

521, 522, 523 or 524: Cloudflare can't reach the server

Check that the server is up and that its firewall lets Cloudflare through. A security plugin or firewall on the server that blocks Cloudflare's addresses gives the same errors. A 524 means the server is reachable but took too long to answer, so look for a slow plugin or an overloaded server. Don't manage the server yourself? Ask your host.

525 or 526: the certificate on the server

The certificate on your server itself is missing or invalid, while Cloudflare's SSL mode wants a good one. Renew it, see SSL & certificate, or set Cloudflare's SSL mode to match what your server has.

1016 or 530: Cloudflare can't find your server

Check that the site's A or CNAME record in Cloudflare points at the right server, for example after a move.

502 or 504 from Cloudflare

Cloudflare got no valid answer from your server. Treat it as a server error.

For your developer

The error page names the Ray ID, which Cloudflare support asks for. Test the server without Cloudflare in between by connecting to its address directly:

curl -sv -o /dev/null --resolve www.example.com:443:192.0.2.1 https://www.example.com/

Cloudflare's block codes (1005 to 1012, 1015, 1020 and 1106) aren't an outage: they count as Checker blocked. Hosting & error pages lists the markup we match.

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