Proxy authentication

Oct 28, 2026Guides

Selenium proxy setup: auth, SOCKS5, Firefox and rotation

Set a Selenium proxy in Chrome and Firefox, add username and password auth tested on Selenium 4.50 and Chrome 154, fix SOCKS5 errors and rotate per driver.12 min read Oct 17, 2026Guides

OkHttp proxy: auth, SOCKS5, rotation and 407 fixes

OkHttp proxy setup in Kotlin and Java for OkHttp 4.12 and 5.x: proxyAuthenticator done right, SOCKS5 logins, the system proxy, rotation and the 407 traps.15 min read Oct 16, 2026Guides

PHP cURL proxy: CURLOPT_PROXY, auth, SOCKS5 and errors

PHP cURL proxy setup that works: CURLOPT_PROXY and PROXYUSERPWD, special characters, SOCKS5 and socks5h, env variables, reuse, rotation and the 407 errors.9 min read Oct 15, 2026Guides

C# HttpClient proxy: WebProxy, auth, SOCKS5 and rotation

C# HttpClient proxy setup for .NET 8 and 10: WebProxy credentials, SOCKS5, environment proxies, IHttpClientFactory, rotation and the 407 and https:// traps.14 min read Oct 10, 2026Guides

407 Proxy Authentication Required: causes and client fixes

A 407 means the proxy, not the site, rejected or never got your login. Causes in the order to check, and the fix for curl, Python, Node, browsers and apt.15 min read