SOCKS5 or SOCKS4? Choosing a proxy protocol for business tools

Many teams first meet SOCKS in a tool's proxy settings, where a drop-down asks for HTTP, SOCKS4 or SOCKS5 and nobody is sure which to pick. SOCKS is a low-level relay: it passes a connection between your device and the destination without reading what travels inside. Because it ignores the content, it can carry much more than web pages. The version numbers suggest a small upgrade, yet the gap between them decides what your tools can do, so this guide sets the two side by side and ends with a recommendation.

The short answer

Pick SOCKS5 for almost everything: it supports UDP, logins and remote DNS. Keep SOCKS4 for legacy software that cannot use anything newer, and remember that a plain HTTP/HTTPS proxy is often simpler for purely web traffic. As a rule of thumb, browsers and data-collection tools run well over HTTP/HTTPS, while SOCKS5 earns its place with non-web traffic and many desktop applications. Our proxies support HTTP, HTTPS and SOCKS5, and an order's protocol can be switched from the dashboard.

How SOCKS differs from an HTTP proxy

An HTTP proxy speaks the language of the web, reading each request, and is made for HTTP and HTTPS traffic. SOCKS sits a layer lower and simply relays raw TCP connections (and UDP, with SOCKS5). As a result it can tunnel traffic an HTTP proxy handles poorly, such as email protocols, games, peer-to-peer connections and other TCP services. What it gives up is any awareness of web content: no inspection and no caching, just bytes passed along.

SOCKS4 in brief

Its age shows in three limits:

• TCP traffic and nothing else. There is no way to carry UDP.
• No login of its own. The protocol defines no standard username and password step, so providers usually control access with IP allowlists.
• IPv4 addressing. The original design deals in IPv4 addresses and leaves the client to look up domain names.

SOCKS4a later allowed a hostname to be passed so the proxy could do the lookup, but the missing UDP and authentication were never added. In a small, controlled environment that may be enough; for most work today it is dated.

SOCKS5 in brief

SOCKS5 closes each of those gaps:

• UDP as well as TCP. Voice, streaming, games and UDP-based DNS can use the proxy too.
• Credentials. A username and password method means access no longer has to rest on IP allowlists alone.
• Lookups on the proxy side. The proxy can resolve domain names itself, keeping the hostnames you visit away from your local resolver.
• Both address families. Destinations can be reached over IPv4 or IPv6.

Of these, remote DNS deserves a closer look. Local resolution means your provider still learns every domain you connect to, although the connections themselves run through the proxy. With SOCKS5 the proxy does the lookup and that gap closes. Our DNS leak test confirms whether your own setup leaks.

Side by side

Encryption is not part of either

It is easy to assume that SOCKS5, being the newer version, encrypts traffic. Neither version does: both simply relay it, and confidentiality has to come from the protocol you send through them, for example HTTPS or an SSH tunnel. Where data needs end-to-end protection, check that the tunnelled protocol provides it.

SOCKS5 from a Python script

Add the SOCKS extra with pip install requests[socks] and requests can use SOCKS5 proxies. Write the scheme as socks5h so that DNS is resolved through the proxy, the safer of the two options:

import requests

proxies = {
    "http": "socks5h://USER:PASS@HOST:PORT",
    "https": "socks5h://USER:PASS@HOST:PORT",
}

r = requests.get("https://httpbin.org/ip", proxies=proxies, timeout=20)
print(r.json())

The HTTP version of the same setup would read http://USER:PASS@HOST:PORT; nothing changes except the prefix.

SOCKS5 from Node.js

In axios, attach a SOCKS agent:

const axios = require("axios");
const { SocksProxyAgent } = require("socks-proxy-agent");

const agent = new SocksProxyAgent("socks5://USER:PASS@HOST:PORT");

axios.get("https://httpbin.org/ip", { httpAgent: agent, httpsAgent: agent })
  .then((res) => console.log(res.data))
  .catch((err) => console.error(err.message));

Choosing the proxy type as well as the protocol

The protocol answers only half the question; the type of IP behind it matters as much. Datacenter proxies suit high-volume work where latency matters. Household or carrier addresses come from residential or mobile proxies, with premium residential for demanding sites. Once everything is set up, our proxy checker confirms the connection and the exit IP.

So the decision is rarely close. You will meet SOCKS4 now and then in older software; SOCKS5 is the practical protocol for current work, with UDP, authentication and remote DNS. Choose it, run an encrypted protocol through it, and test the setup before the team depends on it.