How each one works
An HTTP proxy receives full HTTP requests and forwards them. For plain HTTP it can read and even modify the request (some add headers that reveal the original client). For HTTPS, the client sends a CONNECT request and the proxy opens a raw tunnel to the destination; the encrypted traffic passes through untouched.
SOCKS5, defined in RFC 1928, doesn't care about the application protocol. The client asks the proxy to open a TCP connection (CONNECT), accept one (BIND), or relay UDP datagrams (UDP ASSOCIATE), then simply passes bytes. Username and password authentication is specified separately, in RFC 1929.
Side by side
| HTTP(S) proxy | SOCKS5 proxy | |
|---|---|---|
| Works at | HTTP(S) proxyApplication layer (HTTP) | SOCKS5 proxySession layer — any TCP, plus UDP |
| Traffic it carries | HTTP(S) proxyHTTP, and HTTPS via CONNECT | SOCKS5 proxyAnything: web, email, FTP, game and voice traffic |
| UDP | HTTP(S) proxyNo | SOCKS5 proxyYes, via UDP ASSOCIATE |
| Can read or modify requests | HTTP(S) proxyPlain HTTP only | SOCKS5 proxyNo — passes bytes through |
| DNS | HTTP(S) proxyResolved by the proxy for HTTP requests | SOCKS5 proxyResolved by the client or the proxy (socks5h) |
| Authentication | HTTP(S) proxyProxy-Authorization header | SOCKS5 proxyUsername/password (RFC 1929) |
| Client support | HTTP(S) proxyAlmost everything | SOCKS5 proxyMost tools; some need configuration |
DNS: the detail that leaks location
With SOCKS5 the client can resolve the hostname itself and send an IP address, or send the hostname and let the proxy resolve it. Many tools spell the second option socks5h://. If you're targeting a location, let the proxy resolve: a lookup made from your own machine can return results for your region, not the proxy's, and reveals the hostname to your local resolver.
Which to use
- Web scraping, browsers, rank trackers → HTTP(S). It's the most widely supported and does everything a web job needs.
- Non-HTTP protocols, or an app that only offers SOCKS → SOCKS5.
- Games, voice, streaming and anything else on UDP → SOCKS5 with UDP support.
- Speed → effectively the same for web traffic; choose on compatibility.
SerpProxies includes HTTP, HTTPS and SOCKS5 on every product, on the same credentials. UDP Residential also supports SOCKS5 UDP associate on the same gateway, for gaming, VoIP and streaming.
