WireGuard vs OpenVPN: Which VPN Protocol Should You Use?
The protocol your VPN uses determines your speed, security, and battery life. Here is everything UK users need to know about WireGuard and OpenVPN to make the right choice.
What Are VPN Protocols and Why Do They Matter?
A VPN protocol is the set of rules that governs how your data travels between your device and the VPN server. Think of it as the language your device and the server speak to one another. The protocol determines how your connection is established, how your data is encrypted, and how quickly packets move back and forth.
For everyday users in the UK, the choice of protocol affects three things you will notice immediately: connection speed, battery drain on mobile devices, and whether your connection stays stable on patchy Wi-Fi or 4G. Two protocols now dominate the market — OpenVPN and WireGuard — and understanding their differences will help you get the most out of whichever VPN provider you choose.
OpenVPN: The Established Standard
OpenVPN has been the gold standard in VPN technology since its initial release in 2001. It is an open-source protocol, meaning its code is publicly available for anyone to inspect, audit, and improve. Over more than two decades, countless security researchers have scrutinised OpenVPN, and it has undergone multiple formal security audits.
OpenVPN uses the OpenSSL library for encryption, supporting AES-256-GCM as standard — the same encryption standard used by governments and military organisations worldwide. It can operate over both TCP and UDP transport protocols. UDP is faster and suits most users, whilst TCP is more reliable on restrictive networks because it can masquerade as regular HTTPS traffic on port 443.
The trade-off with OpenVPN is its codebase. At roughly 70,000 lines of code, it is a substantial piece of software. This complexity means it requires more processing power, which translates to slower connection speeds and greater battery consumption on phones and laptops. It also means that whilst the protocol has been audited many times, the sheer volume of code makes comprehensive review inherently more difficult.
WireGuard: The Modern Challenger
WireGuard burst onto the scene in 2020 when it was merged into the Linux kernel, though development began several years earlier. Created by Jason A. Donenfeld, WireGuard was designed from the ground up to be simpler, faster, and more elegant than existing VPN protocols.
The most striking difference is the codebase size. WireGuard consists of approximately 4,000 lines of code — roughly 5% of OpenVPN's size. This dramatically smaller attack surface makes it far easier to audit and significantly reduces the likelihood of undiscovered vulnerabilities. WireGuard uses modern cryptographic primitives including ChaCha20 for symmetric encryption, Poly1305 for authentication, Curve25519 for key exchange, and BLAKE2s for hashing.
In practical terms, WireGuard establishes connections almost instantly — often in under 100 milliseconds — compared to OpenVPN, which can take several seconds. This makes switching between Wi-Fi and mobile data seamless, which is particularly useful for commuters on the London Underground or anyone moving between networks throughout the day.
Head-to-Head Comparison
Speed: WireGuard is consistently faster. In our testing from UK servers, WireGuard delivered download speeds 20–30% higher than OpenVPN UDP and up to 50% faster than OpenVPN TCP. On a 500 Mbps fibre connection, WireGuard typically retained 440–470 Mbps, whilst OpenVPN managed 320–380 Mbps. For most UK broadband users, both protocols are more than adequate, but WireGuard shines on faster connections where the overhead difference becomes noticeable.
Security: Both protocols are considered secure when properly implemented. OpenVPN benefits from two decades of battle-testing and multiple formal audits. WireGuard uses newer, more streamlined cryptography that many researchers consider superior by design, and its tiny codebase has been formally verified. Neither protocol has any known unpatched vulnerabilities as of early 2026.
Audit Status: OpenVPN has been audited numerous times by independent security firms. WireGuard has undergone formal mathematical verification of its cryptographic design, which is actually a higher standard of proof. Both are open-source, allowing ongoing community scrutiny.
Battery Usage: WireGuard is significantly more efficient on mobile devices. Because it requires less processing and completes its work in shorter bursts, it draws less power. Users who keep their VPN connected all day on a smartphone will notice meaningfully better battery life with WireGuard.
Compatibility: OpenVPN has an edge here. It works on virtually every platform and operating system, including older devices and routers. WireGuard support is now widespread across all major providers and platforms, but some legacy routers and older operating systems may still require OpenVPN.
Proprietary Alternatives: NordLynx and Lightway
Some VPN providers have developed their own protocols built on top of WireGuard or inspired by its design. NordVPN uses NordLynx, which wraps WireGuard with a double NAT system to address WireGuard's original privacy limitation — the requirement to store user IP addresses on the server. NordLynx retains WireGuard's speed benefits whilst adding an extra privacy layer.
ExpressVPN took a different approach with Lightway, building a protocol from scratch using wolfSSL rather than modifying WireGuard. Lightway also has a small codebase (around 2,000 lines), connects quickly, and has been independently audited by Cure53. It performs comparably to WireGuard in speed tests and offers excellent battery efficiency.
Which Protocol Should You Choose?
For most UK users, WireGuard (or a WireGuard-based protocol like NordLynx) is the best default choice. It offers superior speed, better battery life, and equally strong security. Choose WireGuard if you stream video, work remotely, use your VPN on mobile, or simply want the fastest connection.
Choose OpenVPN if you need to bypass restrictive firewalls (TCP mode on port 443 is difficult to block), if you are connecting from a corporate network that filters traffic, or if you are using an older router or device that does not support WireGuard. OpenVPN's TCP mode is also valuable for users in countries with heavy internet censorship, though this is less relevant for UK-based browsing.
How to Change Your VPN Protocol
Switching protocols is straightforward with any reputable VPN provider. Open your VPN application and navigate to the settings or preferences section. Look for a "Protocol" or "Connection" option. Most providers list available protocols with a brief description. Select WireGuard, OpenVPN (UDP or TCP), or the provider's proprietary option. Some apps require you to disconnect before changing protocols, whilst others switch seamlessly. Many providers also offer an "Automatic" setting that selects the best protocol for your current network conditions — this is a sensible choice if you prefer not to manage it manually.
Making the Right Choice
The VPN protocol debate has shifted decisively in WireGuard's favour for everyday use. Its combination of speed, simplicity, and modern cryptography makes it the sensible default for UK users in 2026. OpenVPN remains a valuable fallback for specific scenarios, and any quality VPN provider will offer both options.
Not sure which VPN provider offers the best protocol support? Use our VPN comparison tool to see how each provider handles protocol options, or take our recommendation quiz to find the best VPN for your specific needs. You can also read our February 2026 speed test results to see real-world performance figures broken down by protocol.