Guide to VPN Protocols

What is OpenVPN?

OpenVPN is a relatively new and highly configurable protocol. ExpressVPN’s version supports both UDP and TCP ports.

UDP stands for User Datagram Protocol. Though it can be configured to run on any port, OpenVPN runs best on a UDP port, which is generally faster. ExpressVPN uses UDP by default unless it is blocked.

TCP stands for Transmission Control Protocol. Unlike UDP, TCP is error-checked, meaning that dropped packets result in retransmission. This results in increased reliability at the expense of latency.

The best thing about OpenVPN is that it’s open source. “Open” may not sound like a good thing for a privacy tool, but it’s actually a huge advantage. If there are any security flaws in the code — and as yet none are known — they will be quickly identified by the open source community. Paired with a strong encryption algorithm, OpenVPN is the most secure VPN protocol available.

ExpressVPN uses OpenVPN by default across all apps that easily support it.


Open source
Extremely secure


Not supported on all devices

How to Configure Your VPN to OpenVPN

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