Server errorsNon-standard, Cloudflare
520Web Server Returned an Unknown Error
A content network could not make sense of what your origin server sent back.
Browse all HTTP status codesWhen you see it
A catch-all from a content delivery network when the origin returned something empty, malformed, or with headers too large to process. The network is working; the server behind it answered in a way that could not be forwarded.
It is the vaguest of the vendor codes, so the origin server log is the only place the real cause will be recorded.
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Status codes
69 of 69 codes. Click a row to copy it.
1xx Informational (4)
2xx Success (10)
3xx Redirection (8)
4xx Client errors (31)
5xx Server errors (16)