The Complete Guide to VPN Protocols Explained
Published on
When choosing a VPN, most people focus on price, speed, and server locations. However, one of the most important factors in determining your VPN experience is the protocol it uses. A VPN protocol is the set of rules and processes that govern how your data is encrypted, transmitted, and received through the VPN tunnel. Different protocols offer different trade-offs between speed, security, and compatibility. This guide explains the major VPN protocols available in 2026, helping you understand which one is best suited to your needs.
WireGuard: The Modern Standard
WireGuard has rapidly become the preferred protocol for most VPN users since its inclusion in the Linux kernel in 2020. Designed from the ground up by cryptographer Jason Donenfeld, WireGuard takes a fundamentally different approach from older protocols. Its codebase consists of roughly 4,000 lines of code, compared to over 100,000 for OpenVPN. This dramatically smaller attack surface makes it easier to audit, less likely to contain vulnerabilities, and more efficient to run.
Performance is where WireGuard truly excels. The protocol consistently delivers higher throughput and lower latency than both OpenVPN and IKEv2 in independent testing. For UK users, this translates to faster browsing, smoother streaming, and quicker downloads. WireGuard's connection time is also significantly faster, typically establishing a connection in under a second compared to several seconds for OpenVPN.
WireGuard uses modern cryptographic primitives including ChaCha20 for encryption, Poly1305 for authentication, Curve25519 for key exchange, and BLAKE2s for hashing. These are all well-regarded, thoroughly vetted algorithms that represent the current state of the art in cryptography.
Several major VPN providers have built proprietary implementations on top of WireGuard. NordVPN's NordLynx adds a double NAT system to address WireGuard's default behaviour of storing connected IP addresses. These customised implementations aim to combine WireGuard's speed advantages with enhanced privacy protections.
OpenVPN: The Battle-Tested Veteran
OpenVPN has been the industry standard for over two decades and remains a solid choice in 2026. It is open-source, extensively audited, and supported by virtually every VPN provider on the market. OpenVPN uses the OpenSSL library for encryption, supporting a wide range of cryptographic algorithms including AES-256-GCM, which is considered unbreakable with current technology.
OpenVPN operates in two modes: UDP and TCP. UDP mode offers faster speeds and is preferred for general use, while TCP mode provides more reliable connections on restrictive networks. The ability to run on any port, including port 443 (the standard HTTPS port), means OpenVPN can be disguised as regular web traffic, making it effective at bypassing firewalls and VPN blocking.
The main drawback of OpenVPN is its relatively slower speed compared to WireGuard. The larger codebase and more complex encryption process introduce additional overhead. However, for users who prioritise proven security and maximum compatibility over raw speed, OpenVPN remains an excellent choice.
IKEv2/IPSec: The Mobile Favourite
Internet Key Exchange version 2, paired with IPSec for encryption, is particularly well-suited to mobile devices. Its standout feature is MOBIKE (Mobility and Multihoming Protocol) support, which allows the VPN connection to seamlessly switch between network interfaces. When your phone transitions from Wi-Fi to mobile data, IKEv2/IPSec maintains the VPN connection without interruption.
This makes IKEv2/IPSec the ideal protocol for UK users who are frequently on the move, switching between home Wi-Fi, office networks, and mobile data throughout the day. The reconnection is virtually instantaneous, meaning you maintain continuous protection without needing to manually reconnect.
IKEv2/IPSec offers strong security credentials, using AES-256 encryption and supporting perfect forward secrecy. Speed is competitive with OpenVPN and generally slightly behind WireGuard. The protocol is natively supported on iOS, macOS, and Windows, meaning it can be configured without installing additional software.
Legacy Protocols: L2TP and PPTP
Layer 2 Tunnelling Protocol (L2TP), typically paired with IPSec for encryption, is an older protocol that is still offered by some VPN providers. L2TP/IPSec provides adequate security but is slower than modern alternatives due to its double encapsulation process. It uses fixed ports, making it easier to block than OpenVPN or WireGuard. For most UK users, there is no compelling reason to choose L2TP/IPSec over newer protocols.
Point-to-Point Tunnelling Protocol (PPTP) is the oldest VPN protocol still in existence and should be avoided entirely. Developed by Microsoft in the 1990s, PPTP has known security vulnerabilities that make it trivially easy to crack. No reputable security expert recommends PPTP for any purpose in 2026. If your VPN provider only offers PPTP, it is time to switch to a different service.
Proprietary Protocols: Lightway and NordLynx
Several VPN providers have developed their own proprietary protocols. ExpressVPN's Lightway is built on the wolfSSL cryptographic library and uses ChaCha20 encryption. It is designed for speed, minimal battery consumption, and fast connection times. Lightway has been independently audited and open-sourced, providing transparency about its security. In testing, Lightway performs comparably to WireGuard, making it an excellent choice for ExpressVPN users.
NordVPN's NordLynx, as mentioned earlier, is built on the WireGuard framework with additional privacy enhancements. It addresses the privacy concern that standard WireGuard implementations require storing a user's IP address on the server by implementing a double Network Address Translation system that eliminates this requirement.
Conclusion: Choosing the Right Protocol
For most UK users in 2026, WireGuard or a proprietary implementation based on it (NordLynx, for example) is the best default choice. It offers the best combination of speed, security, and battery efficiency. OpenVPN is the preferred fallback for situations where WireGuard is blocked or unavailable, and IKEv2/IPSec is ideal for mobile users who need seamless network switching. Avoid PPTP entirely and treat L2TP/IPSec as a last resort.
Use our free VPN comparison tool at FreeVPNDownload.co.uk to compare which protocols each VPN provider supports. Our detailed comparison includes protocol availability, speed scores, and security ratings, helping you find a provider that offers the right protocol options for your needs.