# HTTP Error Response codes

| Error code                              | Description                                                                                             |
| --------------------------------------- | ------------------------------------------------------------------------------------------------------- |
| **400 Bad Request**                     | Request did not contain a host to connect to or if there was a generic error when validating a request. |
| **403 Forbidden**                       | Error when validating ACL for request.                                                                  |
| **407 Proxy Authentification Required** | Request lacks proxy authentication information, or username or password is invalid.                     |
| **429 Hard limit reached**              | Hard limit value reached, sending additional IP requests is blocked.                                    |
| **500 Internal server error**           | Proxy server has encountered an internal error.                                                         |
| **502 Bad Gateway**                     | Error when request proxying encountered an error.                                                       |
| **504 Timeout**                         | A proxy server did not receive a response from the upstream server in time. Try again.                  |
| **525 Exit node missing**               | Error shown when no exit node was found to complete the request.                                        |