HTTP 412 Precondition Failed vs 525 SSL Handshake Failed
HTTP 412 (Precondition Failed) is a 4xx Client Error response, while 525 (SSL Handshake Failed) is a 5xx Server Error response. 412 indicates that one or more conditions in the request headers (If-Match, If-Unmodified-Since) evaluated to false. In contrast, 525 means that cloudflare-specific. SSL/TLS handshake with the origin server failed.
Description
One or more conditions in the request headers (If-Match, If-Unmodified-Since) evaluated to false.
When You See It
When using conditional requests with ETags and the resource has changed.
How to Fix
Refresh the ETag/Last-Modified value and retry with updated preconditions.
Description
Cloudflare-specific. SSL/TLS handshake with the origin server failed.
When You See It
When origin SSL certificate is expired, misconfigured, or incompatible.
How to Fix
Check origin SSL certificate validity. Ensure TLS version compatibility. Renew expired certificates.
Key Differences
412 is a 4xx Client Error response, while 525 is a 5xx Server Error response.
HTTP 412: One or more conditions in the request headers (If-Match, If-Unmodified-Since) evaluated to false.
HTTP 525: Cloudflare-specific. SSL/TLS handshake with the origin server failed.
You encounter 412 when when using conditional requests with ETags and the resource has changed.
You encounter 525 when when origin SSL certificate is expired, misconfigured, or incompatible.
When to Use Which
For 412 (Precondition Failed): Refresh the ETag/Last-Modified value and retry with updated preconditions. For 525 (SSL Handshake Failed): Check origin SSL certificate validity. Ensure TLS version compatibility. Renew expired certificates.