HTTP 301 Moved Permanently vs 523 Origin Is Unreachable
HTTP 301 (Moved Permanently) is a 3xx Redirection response, while 523 (Origin Is Unreachable) is a 5xx Server Error response. 301 indicates that the resource has been permanently moved to a new URL. All future requests should use the new URL. Search engines will transfer link equity to the new URL. In contrast, 523 means that cloudflare-specific. Cloudflare could not reach the origin server (DNS resolution failed or no route).
Description
The resource has been permanently moved to a new URL. All future requests should use the new URL. Search engines will transfer link equity to the new URL.
When You See It
After domain migrations, URL restructuring, or when consolidating duplicate URLs.
How to Fix
Update links and bookmarks to the new URL in the Location header. For SEO, this is the preferred redirect for permanent moves.
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.
Key Differences
301 is a 3xx Redirection response, while 523 is a 5xx Server Error response.
HTTP 301: The resource has been permanently moved to a new URL. All future requests should use the new URL. Search engines will transfer link equity to the new URL.
HTTP 523: Cloudflare-specific. Cloudflare could not reach the origin server (DNS resolution failed or no route).
You encounter 301 when after domain migrations, URL restructuring, or when consolidating duplicate URLs.
You encounter 523 when when Cloudflare's DNS for the origin fails to resolve.
When to Use Which
For 301 (Moved Permanently): Update links and bookmarks to the new URL in the Location header. For SEO, this is the preferred redirect for permanent moves. For 523 (Origin Is Unreachable): Verify DNS records in Cloudflare dashboard. Check origin server's IP address.