To authenticate proxies in Python, you need to provide the proxy credentials in your HTTP client or library. Most proxy providers use either username/password authentication or IP whitelisting, so make sure you’re using the method your provider requires.
If authentication fails, verify the proxy host, port, username, password, and protocol (HTTP, HTTPS, or SOCKS). Testing the proxy with a simple request to an IP-check service is a quick way to confirm whether your configuration is correct before troubleshooting your code.
Providers like Bright Data, Oxylabs, Decodo (formerly Smartproxy), SOAX, and NetNut offer Python examples and SDKs that simplify proxy authentication and integration.
If the same proxy works in your browser but not in Python, the issue is usually with your application’s configuration rather than the proxy itself.