What Are the Similarities and Differences Between SOCKS4 and SOCKS5 Proxies?

What are the similarities and differences between SOCKS4 and SOCKS5 proxies? And just how exactly do the similarities and differences affect you? Read on through this piece to find out.

If you’ve used the internet for any length of time, you’ve realized how important online privacy can be to users. An entire field of study called cybersecurity concerns itself with tools and methods to ensure that data transmitted through the internet is handled within their protocols. These days, you may recognize advanced internet privacy tools like VPNs and proxies.

However, data privacy is subjective. It depends on what your intentions are, as well as which channel the data will go through. 

In many cases, people often use proxies for functions beyond data security. For instance, you’ll need proxies if you’re into web scraping.

But proxies themselves have their own subcategories based on the SOCKS internet protocol. Today, we have SOCKS4 and SOCKS5 proxies. 

DNS resolution depends on the client mode you use. For example, SOCKS4 and SOCKS5 often resolve hostnames locally, while SOCKS4a and SOCKS5h send the hostname to the proxy for resolution.

What’s SOCKS?

TCP traffic accounts for more than 90% of all global internet traffic, and SOCKS4 was built with exactly that reality in mind.

SOCKS is a proxy protocol that relays traffic between a client and a destination server, and in SOCKS4, the entire model is built around simple TCP-based proxying with no real method negotiation required.

In SOCKS5, the client and server first negotiate an authentication method, which can include no authentication, username/password, or other supported methods, depending on the implementation.

SOCKS development started in 1992 as a security protocol for more effective firewalls and other internet security products. However, it has been made publicly available and has experienced iterations through SOCKS4 and SOCKS5.

There exists a need to provide a general framework for these protocols to transparently and securely traverse a firewall. There exists, also, a need for strong authentication of such traversal in as fine-grained a manner as is practical.

Source: Marcus Leech et al., RFC 1928: SOCKS Protocol Version 5 (IETF, 1996)

People used the SOCKS IP as a bypass tool for restricted internet content. Although its SOCKS proxies aren’t encrypted, they work well as a decoy interface for more secure IPs. Also, SOCKS birthed the idea of port forwarding, allowing users to access servers outside the predefined ports.

Also read: Web Scraping With Proxies

SOCKS4 Proxy

SOCKS4 is a version of IP that works on IPv4 addresses. Put simply, these proxies allow you access to blocked servers and sites using an IPv4 connection. 

You can have SOCKS4 proxies in three kinds, based on proximity:

1. Elite
2. Anonymous
3. Transparent

You can get them in a server list, which a vendor can sell you, together with proxy IP & port, city, and region.

SOCKS4a: the practical upgrade to SOCKS4

SOCKS4a is a small but important extension of SOCKS4. The key difference is that instead of forcing the client to resolve the destination hostname locally and then send an IPv4 address to the proxy, SOCKS4a lets the client send the hostname to the proxy itself.

In practical terms, that changes where DNS resolution happens. With plain SOCKS4, the client usually resolves the hostname locally first. With SOCKS4a, the proxy resolves the hostname instead.

This matters for two reasons. First, it can reduce local DNS exposure because the hostname is handed to the proxy rather than resolved on the client side. Second, it makes SOCKS4a more convenient when you want to work with hostnames directly instead of manually resolving destination IPs.

That said, SOCKS4a is still a legacy extension, not a full replacement for SOCKS5. It does not add UDP support, and it does not give you the broader address handling and protocol flexibility that SOCKS5 provides. 

Also read: Exploring the Advanced Capabilities of SOCKS5 Proxies

SOCKS5 Proxy

SOCKS5 is the newer major version of the SOCKS protocol. Compared with SOCKS4 and the SOCKS4a extension, it adds method negotiation, UDP support, and broader destination handling through IPv4, domain names, and IPv6.

For most modern users, that makes SOCKS5 the more practical default. It is better suited to modern applications, authenticated proxy setups, and environments where hostname handling or UDP compatibility matters.

Also read: Top 5 Best SOCKS5 Proxies

Similarities between SOCKS4 and SOCKS5

While we’ve established that SOCKS5 has succeeded SOCKS4, you may want to know how both proxy types are similar. That’s especially important if you’re paying for proxies and want to know what type works best for its cost.

Below are the areas where both proxies share similarities:

1. Low-Cost Data Protection

Both SOCKS4 and SOCKS5 proxies let you send data requests anonymously to a server. In this way, they protect you from having to give your true IP location to the server admin. 

Some of the real-world cases in which any of the two proxies can come in handy are:

• Accessing geo-restricted content from a website
• Bypassing anti-scraping bot countermeasures
• Avoiding high location-based traffic

However, it bears mentioning that both SOCKS proxies have no encryption protocols. They are best suited for instances where data security isn’t as high a priority as an anonymous high-speed connection.

2. Faster Connections

Speaking of speed, another similarity between SOCKS4 and SOCKS5 proxies is the fast IP connections you get to enjoy with them. This is because they don’t add the extra step of encrypting your data. Neither do they stop to look at what your packets contain. 

This makes for faster request and response rates from the server. It’s precisely for this reason that SOCKS proxies are excellent for web scraping.

Also read: What’s SOCKS5 and How Do You Use It?

Differences between SOCKS4 and SOCKS5

1: TCP-only vs TCP + UDP support

SOCKS4 is the older, simpler version of the protocol and is generally used for TCP-based connections only. SOCKS5 expands that model by supporting TCP as well as UDP through its UDP ASSOCIATE command.

In practical terms, SOCKS4 can still work for straightforward browser traffic or older tooling that only needs TCP. SOCKS5 is more flexible for modern applications because it can handle a wider mix of traffic patterns, especially when UDP matters.

2: No real auth in SOCKS4 vs auth methods in SOCKS5

SOCKS4 does not have the same method-negotiation model as SOCKS5. SOCKS5 begins with a method-selection step where the client and server agree on how authentication will work. Depending on the server setup, that can mean no authentication, username/password, or other supported methods.

This does not mean SOCKS5 encrypts your traffic. It means SOCKS5 gives proxy operators more control over who can use the proxy and how access is negotiated.

3: IPv4-only legacy behavior vs domain-name and IPv6 support

SOCKS4 is tied to older IPv4-style behavior. A later extension, SOCKS4a, improved this by allowing hostnames to be sent to the proxy instead of forcing the client to resolve the destination locally first.

SOCKS5 goes further by formally supporting multiple address types, including IPv4 addresses, domain names, and IPv6 addresses. That makes SOCKS5 a better fit for modern environments and a cleaner default choice for most users.

4: Local DNS vs proxy-side DNS behavior

Another practical difference is where hostname resolution happens. With plain SOCKS4 and plain SOCKS5, many clients resolve the hostname locally before connecting through the proxy. With SOCKS4a and SOCKS5 hostname-based modes, the hostname is passed to the proxy, so the proxy performs the lookup instead.

This matters when you want cleaner proxy-side resolution, fewer local DNS leaks, or better compatibility with destination hostnames rather than raw IPs. It is also one of the easiest ways to explain why SOCKS4a and SOCKS5h exist in real tools.

Also read: SOCKS5 Proxy Settings

Wrapping Up

You might want to consider the similarities and differences between SOCKS4 and SOCKS5 proxies if you care about the security of remote client-server connections. Understanding these details will help you decide which proxy is best suited for your needs. 

If you’d like to try out fast, affordable, responsive, and reliable SOCKS5 proxies, you should check out KocerRoxy. They’ve got proxy lists with IPs from across dozens of countries. After one low payment, you can get started on your project right away.

FAQs About SOCKS4 and SOCKS5 Proxies

Q1. What is a SOCKS proxy?

A SOCKS (Socket Secure) proxy is an internet protocol that routes data packets between a client and server through a proxy connection. It masks your real IP address, allowing anonymous browsing, access to geo-restricted content, and bypass of anti-scraping measures.

Unlike HTTP proxies, SOCKS proxies handle any type of traffic without inspecting packet contents, making them faster for general use.

Q2. What is the difference between SOCKS4 and SOCKS5?

SOCKS4 supports only TCP traffic and IPv4 addresses, with no authentication or UDP support. SOCKS5 is the upgraded version. It supports both TCP and UDP traffic, IPv4 and IPv6 addresses, and multiple authentication methods, including username/password.

SOCKS5 also sends smaller data packet batches per request, resulting in faster, more stable connections and better compatibility across protocols and applications.

Q3. Does SOCKS5 encrypt traffic?

No, SOCKS5 does not encrypt traffic. It routes your data through a proxy server to mask your IP address, but the data itself remains unencrypted. For encrypted connections, you need to pair SOCKS5 with SSL/TLS or a VPN. Despite lacking encryption, SOCKS5 is valued for its speed, anonymity, and versatility across different traffic types and protocols.

Q4. Is SOCKS4 or SOCKS5 faster?

Both SOCKS4 and SOCKS5 offer fast connections because neither encrypts data nor inspects packet contents. However, SOCKS5 is generally faster in practice. It transmits smaller data packet batches per request and supports UDP, which reduces latency.

For high-volume tasks like web scraping, SOCKS5’s optimized packet handling also lowers the risk of triggering anti-scraping detection systems.

Q5. Can SOCKS5 be used for web scraping?

Yes, SOCKS5 is widely used for web scraping. It routes requests through anonymous IPs, helping bypass geo-restrictions and anti-scraping bot countermeasures. Its support for UDP and smaller packet batches reduces the chance of triggering rate limits or detection systems.

SOCKS5 also allows multiple concurrent requests at speed, making it more efficient than SOCKS4 for large-scale scraping operations.

Q6. What traffic types does SOCKS5 support?

SOCKS5 supports both TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) traffic. TCP handles reliable, ordered data transmission for tasks like web browsing and email, while UDP enables faster, lower-latency data flow for applications like video streaming, gaming, and IPTV.

This dual-protocol support makes SOCKS5 significantly more versatile than SOCKS4, which handles TCP traffic only.