HTTP 206 Partial Content vs 520 Web Server Returned an Unknown Error
HTTP 206 (Partial Content) is a 2xx Success response, while 520 (Web Server Returned an Unknown Error) is a 5xx Server Error response. 206 indicates that the server is delivering only part of the resource due to a Range header sent by the client. Used for resumable downloads and video streaming. In contrast, 520 means that cloudflare-specific. The origin server returned an unexpected response that Cloudflare could not process.
Description
The server is delivering only part of the resource due to a Range header sent by the client. Used for resumable downloads and video streaming.
When You See It
During video streaming, large file downloads, or when resuming interrupted downloads.
How to Fix
No fix needed. This is normal behavior for range requests.
Description
Cloudflare-specific. The origin server returned an unexpected response that Cloudflare could not process.
When You See It
When Cloudflare receives an empty, unknown, or malformed response from the origin.
How to Fix
Check origin server logs. Ensure responses include proper headers. Verify SSL configuration.
Key Differences
206 is a 2xx Success response, while 520 is a 5xx Server Error response.
HTTP 206: The server is delivering only part of the resource due to a Range header sent by the client. Used for resumable downloads and video streaming.
HTTP 520: Cloudflare-specific. The origin server returned an unexpected response that Cloudflare could not process.
You encounter 206 when during video streaming, large file downloads, or when resuming interrupted downloads.
You encounter 520 when when Cloudflare receives an empty, unknown, or malformed response from the origin.
When to Use Which
For 206 (Partial Content): No fix needed. This is normal behavior for range requests. For 520 (Web Server Returned an Unknown Error): Check origin server logs. Ensure responses include proper headers. Verify SSL configuration.