VPN protocols: which one to use, and when

A VPN protocol is the set of rules your app and the VPN server use to build an encrypted connection and move your traffic through it. The protocol you choose sets the ceiling on your speed, decides how well the connection survives a dropped signal, and determines how easily a restrictive network can block it. Most modern VPN apps let you switch protocols in one menu — this guide shows which one to switch to.

The facts below come from each protocol's published specification and reputable dated sources, not from speed tests we ran ourselves. We don't publish numbers we didn't measure. Where a claim depends on your hardware or your provider, we say so.

The short answer: which VPN protocol should you use?

For almost everyone, WireGuard is the right default: it is the fastest mainstream protocol, uses modern cryptography, and is easy on battery. Switch to something else only for a specific reason. Choose OpenVPN on TCP port 443 when a network actively blocks VPNs; choose IKEv2 if your connection keeps dropping as you move between Wi-Fi and mobile data. Everything after this is the detail behind that rule.

Protocol vs encryption: the distinction that changes your choice

A protocol and a cipher are two different layers, and confusing them leads people to pick badly. The protocol (WireGuard, OpenVPN, IKEv2) sets up the connection, exchanges keys and moves packets. The cipher (ChaCha20-Poly1305 or AES-256-GCM) scrambles the actual data inside. The protocol decides which cipher runs.

This is why a provider advertising "military-grade AES-256" is telling you almost nothing useful — AES-256 is a public standard used by half the software on your phone, and it says nothing about the protocol carrying it. If you want the encryption layer in plain English, read what encryption VPNs actually use. For choosing a protocol, focus on the outer layer.

WireGuard — the modern default

WireGuard is the protocol most people should leave switched on. It is fast, modern and remarkably small — roughly 4,000 lines of code, against the hundreds of thousands behind OpenVPN and IPsec — which makes it far easier for security researchers to audit. It has shipped inside the Linux kernel since version 5.6 in 2020, and every major provider now offers it.

It is also "cryptographically opinionated": rather than let you negotiate ciphers, it fixes one modern set — ChaCha20-Poly1305 for encryption, Curve25519 for key exchange, BLAKE2s for hashing. Fewer options means fewer ways to misconfigure it. The trade-offs are that WireGuard speaks only UDP, so it is easy for a network to block, and its base design assigns each user a stable internal IP — a privacy wrinkle that good providers engineer around, covered below.

For the full walk-through, see WireGuard explained.

OpenVPN — the compatibility veteran

OpenVPN is the protocol to reach for when WireGuard can't get through. Released in 2001 and open source ever since, it has been independently audited multiple times and is trusted precisely because it is old, boring and well understood. Its superpower is flexibility: it can run over UDP for speed or over TCP on port 443, where its traffic looks like ordinary HTTPS and slips past most VPN blocks.

That flexibility costs speed. OpenVPN's large codebase and per-packet overhead make it slower than WireGuard, and its TCP mode can suffer the "TCP-over-TCP meltdown", where a reliable protocol wrapped inside another reliable protocol triggers redundant retransmissions and stalls. It typically defaults to AES-256-GCM and, since version 2.5, can also use ChaCha20-Poly1305.

More detail is in OpenVPN explained, and the direct comparison is in WireGuard vs OpenVPN.

IKEv2/IPsec — the mobile specialist

IKEv2 is the protocol to choose if your VPN keeps dropping when you move around. Defined in RFC 7296 and co-developed by Microsoft and Cisco, it pairs with IPsec to encrypt traffic and includes a feature called MOBIKE that lets a session survive a change of network — walking out of Wi-Fi range onto cellular without dropping the tunnel. It is built into iOS, macOS and Windows, so it connects quickly with no extra app.

Its weakness is that it uses fixed UDP ports (500 and 4500), which makes it one of the easiest protocols for a firewall to block simply by closing those ports. This is the consumer, mobile-facing side of IKEv2; the enterprise, site-to-site IPsec story is a different topic. We cover the phone-and-laptop angle in IKEv2/IPsec for consumers.

The older protocols you can safely skip

If your app still lists L2TP/IPsec, SSTP or PPTP, you can ignore all three for normal use. L2TP/IPsec double-wraps your data, which makes it slower with no real security advantage over IKEv2. SSTP is a Windows-only, closed-source protocol that rides TCP 443 like OpenVPN but with far less scrutiny. PPTP is the one to actively avoid: its authentication was broken years ago, and it should be treated as unencrypted.

Rule of thumb: if a free or unknown VPN offers only PPTP or L2TP, that is a signal to walk away. Modern providers lead with WireGuard.

Proprietary protocols: NordLynx, Lightway and Catapult Hydra

Several providers ship their own protocols, and the good ones are worth understanding rather than dismissing. NordLynx, from NordVPN, is WireGuard with a custom "double NAT" system bolted on so the server never has to store a table linking you to a fixed internal IP — that is Nord's answer to WireGuard's privacy wrinkle. It is an affiliate link; we may earn a commission if you sign up, and it never changes what we write here.

Lightway, from ExpressVPN (also an affiliate link), is a lean, open-source protocol; the company rewrote it in Rust and released that version publicly in February 2025, and independent auditors reviewed the new code in 2024 with no critical findings. Catapult Hydra, from Hotspot Shield, is closed-source and speed-focused — fine for streaming, less transparent for privacy. The pattern to watch: proprietary protocols built openly on WireGuard or reviewed by outside auditors are trustworthy; closed ones you have to take on faith.

The full breakdown is in proprietary VPN protocols explained.

The full comparison table

Here is every mainstream option in one place, ranked by how often it is the right pick for a typical person.

How to pick by what you're doing

For streaming and downloads, use WireGuard for the highest throughput. For gaming, WireGuard again — its UDP transport keeps latency low. For a phone that hops between networks all day, IKEv2 recovers most gracefully, with WireGuard a close second. When a school, office or hotel network blocks VPNs outright, OpenVPN on TCP 443 is the reliable escape hatch. Our protocol-by-use-case guide goes device by device.

One recurring choice is TCP versus UDP. Use UDP by default for speed; switch to TCP only when UDP is being blocked, accepting the slowdown. The mechanics are in TCP vs UDP for VPN.

What "secure" actually means here

All three mainstream protocols are secure in the sense that matters: with modern ciphers and default settings, no one can read your traffic in transit. What a VPN does not do is make you anonymous. It moves your trust from your internet provider and local network to the VPN company — which is why the provider's no-logs policy and independent audits matter as much as the protocol. No protocol makes you untraceable. We spell out the threat model in are VPN protocols safe.

Because independence is the whole point of a no-logs claim, it is worth naming providers that pay us nothing: Mullvad and Proton VPN both run WireGuard, publish their apps openly, and are as easy to recommend as any brand with an affiliate program. Choose the protocol on the specs; choose the provider on its record.

Common mistakes when choosing a protocol

The most common mistake is hunting for "the most secure protocol" as if the others were leaky. With modern settings, WireGuard, OpenVPN and IKEv2 are all secure — nobody is reading your traffic on any of them. The real differences are speed, how easily each is blocked, and how well it survives a network switch. Once you accept that safety is a tie, the choice becomes a practical one about your situation, and it gets much easier.

A second mistake is leaving the app on OpenVPN because it "sounds safer", and quietly paying for it in speed and battery every day. OpenVPN is the backup for blocked networks, not the daily driver. The mirror-image error is judging a whole VPN by the cipher on its marketing page: "AES-256" is the same cipher almost everything uses, so it tells you nothing about the protocol carrying it or the company behind it.

Finally, people blame the protocol when a connection is slow, then switch protocols and see no change. Nine times out of ten the culprit is the server — too far away or overloaded — or the underlying line, not the protocol. Change the server first. Keep WireGuard on, move OpenVPN to the backup slot, and don't let a cipher name do your thinking, and you have made the decision correctly.