OpenVPN vs IKEv2
IKEv2 is the protocol your phone already has and the one that survives walking out of the house mid-call. OpenVPN is the one that still connects when a firewall is trying to stop you. Neither wins outright.
See our protocol stackThe short version
| OpenVPN | IKEv2/IPsec | |
|---|---|---|
| Built into iOS / Windows | No | Yes |
| Transport | TCP or UDP | UDP 500 / 4500 |
| Can use port 443 | Yes | No |
| Survives network changes | Reconnects | Seamless |
| Connection speed | Slower | Very fast |
| Blocked by strict firewalls | Rarely | Often |
| Open source | Yes | Implementation-dependent |
| Best for | Restrictive networks | Phones and tablets |
What each one is genuinely good at
IKEv2: mobility
MOBIKE, the mobility extension, lets a session survive a change of network without renegotiating. Leave the house, drop off Wi-Fi onto mobile data, and the tunnel simply continues — no dropped call, no interrupted download. This is why it is a common default on phones.
IKEv2: nothing to install
Native support in iOS, macOS, Windows and most Android builds means it works from the operating system’s own VPN settings without a third-party client. On a locked-down corporate device that may be the only option available to you.
OpenVPN: gets through
Running over TCP on port 443, OpenVPN traffic sits on the same port as every HTTPS connection on the internet. Blocking it means blocking the web. IKEv2 uses fixed UDP ports 500 and 4500, which a firewall can close without breaking anything else — and frequently does.
OpenVPN: fully auditable
Open source, two decades of public scrutiny, and the same code on every platform. IKEv2 is a standard rather than a program, so what you actually get depends on whose implementation is running — and some of those are closed.
Are they equally secure?
In practice, yes. Both support modern cipher suites, both have been in wide deployment for many years, and neither has a known practical break when properly configured. Security differences between them come from implementation and configuration, not from the protocols themselves.
IKEv2 carries a specific piece of historical baggage. Documents published in 2014 suggested that IPsec had been a target for weakening, and the discussion has never entirely settled. Nothing has been demonstrated against a correctly configured modern deployment, but it is why some privacy-focused users prefer to avoid the IPsec family where they have a choice.
OpenVPN’s weakness is different and more mundane: it is large, old and highly configurable, which means a badly configured OpenVPN server is entirely possible. The protocol gives you enough rope. That flexibility is exactly what makes it valuable on hostile networks, and exactly what makes it easier to get wrong.
For most people this is not a choice worth making manually. A well-built client picks the right protocol for the network you are on and switches when conditions change. We default to WireGuard for speed and battery life, and fall back automatically — with obfuscation — when a network is actively filtering VPN traffic.
Common questions
Is IKEv2 faster than OpenVPN?
Which should I use on my phone?
Why does IKEv2 fail on hotel and airport Wi-Fi?
Is OpenVPN obsolete now that WireGuard exists?
Related reading
The right protocol, chosen for you
LunoVPN picks the protocol that works on the network you are actually on, and tells you which one it used.