HTTP 408 Request Timeout vs 526 Invalid SSL Certificate
HTTP 408 (Request Timeout) is a 4xx Client Error response, while 526 (Invalid SSL Certificate) is a 5xx Server Error response. 408 indicates that the server timed out waiting for the request. The client did not produce a request within the time the server was prepared to wait. In contrast, 526 means that cloudflare-specific. The origin's SSL certificate could not be validated.
Description
The server timed out waiting for the request. The client did not produce a request within the time the server was prepared to wait.
When You See It
When a client takes too long to send the complete request (slow upload, network issues).
How to Fix
Retry the request. Check your network connection. Reduce request payload size.
Description
Cloudflare-specific. The origin's SSL certificate could not be validated.
When You See It
When using Cloudflare Full (Strict) mode with an invalid origin certificate.
How to Fix
Install a valid SSL certificate on the origin, or use Cloudflare Origin CA certificate.
Key Differences
408 is a 4xx Client Error response, while 526 is a 5xx Server Error response.
HTTP 408: The server timed out waiting for the request. The client did not produce a request within the time the server was prepared to wait.
HTTP 526: Cloudflare-specific. The origin's SSL certificate could not be validated.
You encounter 408 when when a client takes too long to send the complete request (slow upload, network issues).
You encounter 526 when when using Cloudflare Full (Strict) mode with an invalid origin certificate.
When to Use Which
For 408 (Request Timeout): Retry the request. Check your network connection. Reduce request payload size. For 526 (Invalid SSL Certificate): Install a valid SSL certificate on the origin, or use Cloudflare Origin CA certificate.