Is Error 525 caused by Cloudflare or my hosting?

The error is reported by Cloudflare, but it is almost always triggered by a misconfiguration or limitation on your origin server (hosting side).

Can I just switch to Flexible SSL to fix Error 525?

Switching from Full or Full (Strict) to Flexible can make Error 525 disappear temporarily because Cloudflare no longer uses HTTPS to reach your origin. However, it weakens security and should only be used as a short-term workaround while fixing the origin SSL configuration.

Does a self-signed certificate work with Cloudflare?

A self-signed certificate can work with Cloudflare Full mode, but it does not work with Full (Strict), which requires a valid certificate signed by a trusted CA or a Cloudflare Origin CA certificate.

Why does HTTPS work in my browser but still show Error 525?

This can happen if Cloudflare connects to the origin using a different hostname or IP than your browser, or if Cloudflare requires stricter checks such as SNI or CA validation. Verifying the exact hostname and certificate used between Cloudflare and the origin is essential.

Can firewall rules cause an SSL handshake failure?

Yes. If a firewall blocks Cloudflare IP ranges or blocks port 443, Cloudflare cannot complete the SSL handshake. Ensure Cloudflare IPs and HTTPS traffic are allowed.

How do I know if TLS versions or ciphers are the problem?

Run an SSL/TLS scan on your origin server and compare the supported protocols and ciphers with Cloudflare’s requirements. Servers limited to outdated protocols or weak ciphers should be updated.

Can restarting the server fix Error 525?

Restarting the server may help if the issue is caused by a stuck process or temporary resource problem. However, certificate issues or protocol mismatches must be fixed in configuration.

When should I involve my hosting support?

Contact hosting support if you cannot confirm certificate installation, TLS or cipher settings, or if HTTPS fails even without Cloudflare. Provide the error time and mention "Cloudflare Error 525 - SSL handshake failed" for faster diagnosis.

Does Cloudflare Origin CA prevent Error 525?

Yes. Cloudflare Origin CA certificates are specifically designed to secure traffic between Cloudflare and your origin server and work reliably with Full (Strict) mode.