400 - Bad request

Proxy server can return this error code if the request did not contain a host to connect to or there was a generic error when parsing HTTP request. Make sure your request is correctly formed and make sure to include URL in the request then try again.

407 - Proxy Authentication Required

Request lacks proxy authentication information or username or password is invalid. Include Proxy authentication header in your request and make sure your username and password are correctly formed and then try again.

500 - Internal Server Error

Proxy server has encountered an internal error. Retry request at a later time.

502 - Bad Gateway

Proxy server received an invalid response from the upstream server. Retry request.

504 - Gateway Timeout

Proxy server did not receive a response from the upstream server in time. Retry request.

525 - No Exit Found

Custom HTTP status code - this means proxy was unable to find an exit node which satisfies the the request. Change request filter parameters or try again at a later time.