WireGuard vs OpenVPN: Speed, Security, and When to Use Each

Key Takeaways

• WireGuard is 3–4x faster than OpenVPN and uses roughly 4,000 lines of auditable code.
• WireGuard runs on UDP only – fast, but blockable on restrictive networks.
• OpenVPN supports TCP port 443, mimicking HTTPS traffic to get through strict firewalls.
• Use WireGuard for everyday browsing and streaming; use OpenVPN when WireGuard is blocked.
• Mysterium VPN uses WireGuard by default and also supports OpenVPN, excluding Android.

WireGuard and OpenVPN get framed as rivals, and that framing causes people to pick wrong. They solve different problems. WireGuard is the protocol for speed and everyday use. OpenVPN is the protocol for when WireGuard won’t connect at all. 

The network decides, not preference. Mysterium VPN uses WireGuard by default and recently added OpenVPN support.

The Two Protocols in Brief

Let’s take a look at the two VPN protocols.

WireGuard

WireGuard was written by Jason A. Donenfeld and reached a stable release in 2019. Its defining trait is size: roughly 4,000 lines of code, against tens of thousands for OpenVPN. It uses a fixed set of modern cryptographic primitives – ChaCha20 for encryption, Poly1305 for authentication, and Curve25519 for key exchange – with no cipher negotiation at all. 

Peers authenticate with public and private key pairs, so a connection comes up almost instantly with no certificate infrastructure to manage. On Linux it runs inside the kernel, and it has since been ported to Windows, macOS, iOS, and Android.

OpenVPN

OpenVPN was released by James Yonan in 2001 and has been in continuous production use ever since. It builds its tunnel using SSL/TLS, authenticates with digital certificates, and runs on OpenSSL, which gives it access to a wide range of ciphers including AES-256. It runs mostly in user space rather than in the kernel, which costs it performance. 

What it buys in return is configurability: transport choice, cipher choice, and integration with enterprise authentication systems including LDAP, RADIUS, and multi-factor setups. Two decades of deployment also mean it runs on almost anything, including hardware nobody has updated since 2014. 

A broader tour of the options is in this guide to VPN protocols explained.

WireGuard vs OpenVPN: Full Comparison

Speed and Performance

The speed gap comes down to where the code runs. 

WireGuard operates inside the operating system kernel, so packets are encrypted and forwarded at the lowest level available. OpenVPN runs largely in user space, so every packet crosses the boundary between user space and kernel space and back again. 

That context switching costs CPU cycles, and the cost compounds under load.

In practice, WireGuard delivers roughly 3–4x higher throughput and lower latency in most real-world conditions. Handshakes complete faster too, which matters more than raw throughput on mobile: a phone moving between Wi-Fi and cellular reconnects almost instantly on WireGuard, where OpenVPN can stall or drop the tunnel. For streaming, gaming, and large file transfers, the difference is not subtle.

OpenVPN Port 443: How OpenVPN Bypasses Restrictive Firewalls

OpenVPN's default is UDP port 1194, but it can also run over TCP port 443 – the same port every HTTPS website uses. That single detail is why OpenVPN is still essential.

Restrictive networks – corporate firewalls, hotel Wi-Fi, university networks, and national filtering systems – commonly block known VPN ports and drop UDP traffic that looks like a tunnel. 

They can’t block TCP 443 without also breaking ordinary web browsing for everyone on the network, so it stays open almost everywhere. OpenVPN traffic on TCP 443 arrives at the firewall looking like a TLS connection to a web server, because at the transport layer that is very close to what it is.

The trade-off is real: TCP inside TCP adds latency and can behave poorly on congested links. Nobody should run OpenVPN over TCP 443 as a daily driver if UDP is available. 

But when WireGuard's UDP traffic is identified and dropped, an OpenVPN connection on TCP 443 will often still come up. WireGuard solves for speed. OpenVPN solves for getting through at all.

When to Use WireGuard vs OpenVPN

• Use WireGuard (UDP) for everyday browsing, streaming, gaming, and any stable network. It is faster, lighter on the CPU, and easier on battery life, and it reconnects cleanly when a device switches networks. This is the default on Mysterium VPN and the right choice roughly all of the time.
• Use OpenVPN (TCP) when WireGuard won’t connect, or when a network is actively filtering VPN traffic. TCP 443 mimics standard HTTPS and passes through most restrictive firewalls. It’s the compatibility fallback, not the daily setting.

WireGuard vs OpenVPN on a Router: Which Works Better?

Both protocols run on routers, with different track records. OpenVPN has been supported in third-party router firmware for well over a decade and works on DD-WRT, OpenWRT, and Tomato builds, including older hardware with modest CPUs. WireGuard arrived later and is now standard in current firmware, though patchier on hardware that is several years old.

Performance inverts that picture. WireGuard's lower processing overhead matters far more on a router's weak CPU than on a laptop, so on modern router hardware it will usually deliver several times OpenVPN's throughput. 

The practical rule: check the firmware, run WireGuard if the router supports it, and fall back to OpenVPN on older hardware. Mysterium VPN works on any Wi-Fi router supporting either protocol, and the VPN for router setup page covers configuration.

Security and Codebase

Both protocols are considered secure when configured correctly. The difference is in how much there is to get wrong.

WireGuard's roughly 4,000 lines make the whole codebase readable by a single reviewer in a sitting, which is a meaningful security property rather than a marketing line – a smaller attack surface is simply a smaller attack surface. 

Its fixed cryptographic suite is a design decision, not a limitation: with no cipher negotiation, there is no downgrade attack and no way to misconfigure the encryption. ChaCha20 encryption in particular performs well on devices without hardware AES acceleration, which covers a lot of phones and routers.

OpenVPN's flexibility is where its risk lives. Supporting many ciphers, authentication methods, and transport options means a deployment can be built exactly to spec, and it also means a deployment can be built badly. Two decades of scrutiny have hardened the code itself; the misconfigurations are the recurring problem.

One structural difference is worth knowing. WireGuard holds peer IP addresses in memory for the duration of an active session, which is a consequence of its stateless-by-design routing rather than a bug, but it does mean a server operator has to clear that state deliberately. OpenVPN allocates and releases session data dynamically and supports ephemeral keys by default. 

This is a genuine point in OpenVPN's favor, and it is the reason a provider's logging architecture matters independently of the protocol it runs.

Which Protocol Does Mysterium VPN Use?

Mysterium VPN uses WireGuard as its default protocol, and Mysterium VPN's WireGuard implementation is what handles most connections. OpenVPN support was added recently and is available on Windows, Mac, iOS, and Linux, though not on Android. 

That combination covers most network scenarios from one app: connect on WireGuard for everyday use, and switch to OpenVPN in app settings when a network blocks WireGuard. Readers who want both protocols on a single subscription can get Mysterium VPN from $2.99/mo on a two-year plan, covering 15 devices at once.