HTTP 523 Origin Is Unreachable vs 524 A Timeout Occurred
Both HTTP 523 (Origin Is Unreachable) and 524 (A Timeout Occurred) belong to the 5xx Server Error category. 523 indicates that cloudflare-specific. Cloudflare could not reach the origin server (DNS resolution failed or no route). Meanwhile, 524 means that cloudflare-specific. A TCP connection was established but the origin didn't respond with an HTTP response in time.
Description
Cloudflare-specific. Cloudflare could not reach the origin server (DNS resolution failed or no route).
When You See It
When Cloudflare's DNS for the origin fails to resolve.
How to Fix
Verify DNS records in Cloudflare dashboard. Check origin server's IP address.
Description
Cloudflare-specific. A TCP connection was established but the origin didn't respond with an HTTP response in time.
When You See It
When a request to the origin takes longer than Cloudflare's 100-second timeout.
How to Fix
Optimize slow endpoints. Move long-running tasks to background jobs.
Key Differences
HTTP 523: Cloudflare-specific. Cloudflare could not reach the origin server (DNS resolution failed or no route).
HTTP 524: Cloudflare-specific. A TCP connection was established but the origin didn't respond with an HTTP response in time.
You encounter 523 when when Cloudflare's DNS for the origin fails to resolve.
You encounter 524 when when a request to the origin takes longer than Cloudflare's 100-second timeout.
When to Use Which
For 523 (Origin Is Unreachable): Verify DNS records in Cloudflare dashboard. Check origin server's IP address. For 524 (A Timeout Occurred): Optimize slow endpoints. Move long-running tasks to background jobs.