> For the complete documentation index, see [llms.txt](https://developers.oxylabs.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developers.oxylabs.io/products/proxies/residential-proxies/additional-information.md).

# Response Codes

Learn about different response codes for Residential Proxies. Understand issues under the codes and resolve common status errors.

When an error originates within the Oxylabs proxy infrastructure, the response includes an `X-Error-Description` **HTTP header** explaining the root cause and recommended action.

{% hint style="warning" %}
If an error originates directly from the target website (e.g., target-side `404` or `403` codes), the `X-Error-Description` header will not be present. Inspect your request headers, TLS fingerprint, or retry logic when debugging target-side errors.
{% endhint %}

<table><thead><tr><th width="119.86328125">Response Code</th><th width="198">Error Message</th><th>Description</th></tr></thead><tbody><tr><td><code>200</code></td><td><code>OK</code></td><td>Tunnel established successfully.</td></tr><tr><td rowspan="4"><code>400</code></td><td rowspan="4"><code>Bad Request</code></td><td>Could not parse the request. Please check if the request is formatted correctly.</td></tr><tr><td>SOCKS version unsupported. Please use SOCKS5 to make requests.</td></tr><tr><td>Unsupported parameters were used. Please contact support or your account manager if you have any questions.</td></tr><tr><td>Invalid HTTP request received. Please try again.</td></tr><tr><td><code>403</code></td><td><code>Access Denied</code></td><td>Restricted target. Please contact support or your account manager if you have any questions.</td></tr><tr><td rowspan="2"><code>407</code></td><td rowspan="2"><code>Access Denied</code></td><td>User authentication failed. Please check your credentials and try again.</td></tr><tr><td>Traffic limit reached. Please contact support or your account manager if you have any questions.</td></tr><tr><td><code>500</code></td><td><code>Internal Server Error</code></td><td>We have encountered an internal error. Please try again.</td></tr><tr><td rowspan="6"><code>502</code></td><td rowspan="2"><code>Bad Response</code></td><td>Invalid HTTP response received during the request. Please try again.</td></tr><tr><td>Invalid response received during the request. Please try again.</td></tr><tr><td rowspan="4"><code>Bad Gateway</code></td><td>Session failed. Please start a new session.</td></tr><tr><td>Exit node not found (session ended). Try using different filters (or start a new session).</td></tr><tr><td>We have encountered an error. Please try again.</td></tr><tr><td>Client disconnected. Please try again.</td></tr><tr><td rowspan="2"><code>504</code></td><td rowspan="2"><code>Timeout</code></td><td>Request timed out. Please try again.</td></tr><tr><td>Unable to reach the target. Please check if the target URL is correct and try again.</td></tr><tr><td><code>522</code></td><td><code>Bad Response</code></td><td>Invalid response received during the request. Please try again.</td></tr></tbody></table>

If you encounter a response code that's not listed here, please reach out to [**Customer Support**](mailto:support@oxylabs.io) or your Account Manager for further assistance.


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