What Is VPN Obfuscation?

To illustrate the difference between unobfuscated and obfuscated VPN traffic, we used Wireshark, a powerful deep packet inspection software.

Here’s what VPN traffic looks like without obfuscation:

Here’s what VPN traffic looks like with obfuscation:

As you can see, without obfuscation, Wireshark detected both WireGuard and OpenVPN protocols. With obfsproxy enabled, it only detected a TCP connection, effectively hiding the VPN usage.

Obfuscated servers are specialized VPN servers that employ obfuscation techniques, to camouflage your VPN connection.

The main advantage of using an obfuscated VPN server is its simplicity. Unlike other obfuscation methods that may require complex configurations, connecting to an obfuscated server typically requires no special settings in your VPN app. Just connect, and your VPN traffic is automatically hidden.

Examples of VPN services offering obfuscated servers include ExpressVPN, which provides obfuscation across its entire network.

Obfuscated servers apply extra layers of encryption and code, which can slow down your internet connection.

Our tests show that VPNs are affected differently by obfuscation technology.

Generally, VPNs best at bypassing firewalls (Astrill VPN, ExpressVPN, and Windscribe VPN) maintain fast to average speeds with obfuscation enabled.

Connecting to obfuscated servers reduced speeds for all tested VPNs, but to varying degrees.

Surfshark and ExpressVPN experienced minimal speed loss when connecting to short and long distance servers with obfuscation enabled. In contrast, PIA’s speeds dropped from 88Mbps on a local US connection to a disappointing 15Mbps on a long-distance UK connection.

Surfshark demonstrated the most impressive download speeds, with only a 1% drop using NoBorders mode on a local server.

However, this comes with a trade-off: Surfshark struggles to bypass the Great Firewall of China, succeeding only 35% of the time in the past year. This suggests its speed might be due to less effective obfuscation.

Every VPN has its own obfuscation technology that works in different ways. If speed is your main concern, we recommend using Surfshark, Astrill VPN, or ExpressVPN.

VPN obfuscation technology is not always reliable. Over the years, we’ve observed that some VPNs periodically succeed and then fail to obfuscate your connection and bypass firewalls.

However, as long as the VPN has a strong no-logs policy and is based outside the 14 Eyes Alliance, your IP address and online activity will be safe from prying eyes.

To further mitigate risks associated with your VPN traffic leaking, we recommend using a VPN with a working kill switch, too.

Pros	Cons
Open-source	No official audit
Fast speeds	No port forwarding
Uses less RAM

Shadowsocks is a free, open-source obfuscation proxy protocol. It’s widely used in China to bypass government censorship undetected.

Based on the SOCKS5 protocol, Shadowsocks reroutes internet connections through a third server, masking your location and disguising VPN traffic as HTTPS.

Unlike regular proxies, which don’t encrypt traffic, Shadowsocks employs AEAD cipher encryption, similar to SSH tunneling. This prevents ISPs from reading your web traffic.

AEAD (Authenticated Encryption with Associated Data) allows recipients to verify data authenticity and integrity. It’s part of the industry-standard AES encryption cipher suites.

Unfortunately, Shadowsocks is uncommon among VPN services due to its complex setup process for both providers and users.

Pros	Cons
Open-source	Rarely used in VPN services
Great for bypassing online censorship and restrictions	Requires manual configuration to be safe
Incredibly fast speeds	Vulnerable to man-in-the-middle-attacks

SoftEther VPN is an open-source, multi-protocol VPN software. It supports Windows, macOS, Linux, FreeBSD, and Solaris, providing fast, low-latency connections capable of bypassing sophisticated firewalls.

SoftEther uses Ethernet over HTTPS to establish VPN tunnels, making it difficult for ISPs and governments to detect. The software supports its own VPN protocol as well as OpenVPN, L2TP/IPSec, L2TPv3, and EtherIP.

The protocol divides TCP connections into uplink and downlink groups, mimicking typical HTTPS connections to evade firewalls and DPI. It also sets time limits on TCP connections to avoid detection of unusually long connections.

Despite its advantages, SoftEther is only available on Hide.me due to its complex setup process for both providers and users.

In 2019, researchers identified two vulnerabilities in Hide.me’s SoftEther implementation: lack of server certificate verification and insufficient authentication for the back-end management interface. Both issues exposed users to potential man-in-the-middle attacks.

Pros	Cons
Open-source software	SSL is more common but outdated
TLS 1.3 was updated in 2018	Difficult to configure manually
Commonly used by VPNs

OpenVPN over SSL (Secure Sockets Layer) or TLS (Transport Layer Security) combines OpenVPN with a layer of SSL or TLS encryption to hide VPN usage from your ISP.

OpenVPN over SSL/TLS obfuscation requires a VPN service to use the open-source Stunnel software. The complexity of the setup process has discouraged widespread adoption.

While OpenVPN over SSL/TLS offers robust encryption, it is not user-friendly for individual users. It’s rare to find VPNs with SSH or SSL enabled, and none of the top-rated VPNs have it configured.

Pros	Cons
Effective at bypassing firewalls	Closed-source
Secure AES-256 encryption	Dubious links with the NSA
Fast speeds

Secure Socket Tunnel Protocol (SSTP) is a secure VPN protocol developed by Microsoft in 2007 to replace the vulnerable PPTP. It supports Windows, Linux, Android, and various routers.

Initially vulnerable to Man-in-the-Middle (Poodle) attacks, SSTP is now secure thanks to TLS 1.2 and 1.3 implementation.

However, SSTP is available with only a few VPNs out of the 61 tested. Hide.me remains the sole top 10 VPN offering SSTP after IPVanish discontinued it in 2022.

Many effective anti-censorship VPNs have moved to more sophisticated systems, abandoning SSTP.

The protocol is now commonly used in Windows 10/11 for secure corporate network connections from remote locations.

Concerns persist due to alleged links between Microsoft and the NSA, revealed by Edward Snowden in 2013. One example is Microsoft’s reported assistance to the NSA in circumventing encryption for Outlook.com web chats.

Pros	Cons
Random handshake patterns	Obfsproxy traffic stands out in comparison to other protocols
Requires less bandwidth	Complex setup for VPN services and servers

Obfsproxy, or Obfuscation Proxy, originated in the Tor community to mask Tor traffic from ISPs.

It uses obfs2, obfs3, scramblesuit, obfs4, or meek to create an obfuscated tunnel for VPN traffic, adding extra encryption.

While lightweight and bandwidth-efficient, Obfsproxy is less secure. Scramblesuit, obfs4, and meek are currently the only protocols with obfsproxy that we would recommend using to bypass censorship, as the others are outdated and easily detected by DPI.

While some VPNs have adopted obfsproxy, the complexity of its setup means it remains relatively rare.

Obfsproxy can disguise your Tor or OpenVPN traffic as any traffic type, but it’s not foolproof against firewalls and DPI. Its traffic stands out due to its random appearance, making it potentially identifiable through entropy tests.

Developed for users in countries with strict online censorship, we’ve observed a decent level of success using it in countries like China or Russia to bypass online firewalls.

Pros	Cons
Open-source	Weak encryption keys
	Inconsistent against sophisticated firewalls
	Hackers use XOR to hide malware

OpenVPN Scramble, or XOR obfuscation, is a third-party OpenVPN patch adding extra obfuscation.

It applies a bitwise XOR cipher to disguise your OpenVPN traffic as UDP traffic.

This method has two major drawbacks: it’s easily decipherable and unreliable for bypassing online firewalls and censors. Our IPVanish tests show its scramble features consistently fail to circumvent the China firewall.

However, StrongVPN’s implementation proves effective against the Great Firewall of China.

Overall, OpenVPN Scramble offers low security and basic obfuscation compared to other tools, providing a rudimentary solution for VPN traffic concealment.

Pros	Cons
Highly customizable	Extremely rare in VPNs
	Complex setup for VPN providers
	Vulnerable to fingerprinting attacks

V2Ray is an open-source platform developed under Project V, providing developers with the VMess protocol to create new proxy software.

Designed to circumvent the Great Firewall of China, V2Ray is more complex to configure compared to Shadowsocks, which prioritizes simplicity.

In July 2024, the first independent security audit of V2Ray concluded that it is “well-protected against a broad range of attack vectors” but can be distinguished from normal traffic.

Auditors discovered three medium-severity vulnerabilities related to fingerprinting attacks, along with several minor issues. While some of these vulnerabilities have been addressed, others are still pending.

VPN.AC is the only VPN service we’ve reviewed that offers V2Ray tunneling. This feature is available exclusively in the Windows app, located in the advanced settings.

Our tests revealed that enabling V2Ray on VPN.AC frequently caused our VPN connection to drop and occasionally blocked us from connecting to the VPN server altogether.

Users can choose between a direct connection through VPN.ac’s obfuscation proxy servers or a connection via Cloudflare.

Journalists and political activists often need unrestricted access to the internet. This way they can freely research, share information, and securely communicate with contacts.

If you deal with sensitive information on a regular basis and you’re based in a country with online firewalls, having a reliable VPN with obfuscation is essential.

Otherwise, regulators using deep packet inspection could identify your web activity or VPN use and flag you as a target for surveillance.

Internet censorship is the control or suppression of information and media published on the internet, often authorized by governments regulators. Network companies may also engage in self-censorship for business or moral reasons.

Online censorship can occur through site blocking, content filtering, and complete internet shutdowns. It occurs more often in anticipation of political events such as elections, protests, and riots.

For example, Russia has banned Instagram, Twitter, Google News, BBC News, and many more websites in 2022. As a result, demand for VPNs that work in Russia rose by more than 2,500% between the months of February and March.

VPNs are excellent at encrypting your data, unblocking websites, and hiding your activity from your ISP, but they are also easy to detect. If you live in a country that bans or punishes the use of VPN services, VPN obfuscation is necessary to bypass these website blocks and firewalls without being detected.

Some torrenting VPNs offer both P2P servers and obfuscated servers separately. Choosing between a P2P or obfuscated server for torrenting will depend on your location.

If you’re based in a country where torrenting is legal or allowed for personal use, we recommend using a VPN with a no logs policy and P2P-optimized servers.

However, if you’re based in a country with strict online firewalls and restrictions, we recommend using a VPN with inbuilt obfuscation, or a VPN with an obfuscation protocol and P2P-optimized servers.

In some cases, it’s best to use a combination of an obfuscated protocol and a P2P-optimized server:

VPN obfuscation will slow down your internet connection speed. Obfuscating your VPN connection involves additional algorithms, codes, and layers of encryption, which means the data packets themselves become larger and take more time to travel between servers.

If you don’t have a high-speed internet connection, obfuscation can crash your online activities or cause lag.

Streaming services like Netflix actively scan for VPN traffic. If they identify a VPN or proxy user, they may block that user from the platform or restrict them to certain titles.

In theory, a tool that hides the fact you are using a VPN should be beneficial for unblocking streaming services.

In reality, we found in our VPN streaming tests that obfuscation protocols and servers didn’t increase the likelihood of bypassing geo-blocks on streaming services.

We also discovered that VPN obfuscation can actually hinder your streaming experience as it can slow down your internet connection, causing your video to buffer or lag.