- IPVanish added OpenVPN Data Channel Offload (DCO) to its Windows app
- Internal testing saw download increases of up to 196%
- The feature cannot be used at the same time as OpenVPN Scramble
IPVanish has released a new Windows client built around High-Speed Mode, the provider’s implementation of OpenVPN Data Channel Offload (DCO). The company claims that the feature increases OpenVPN download speeds by up to 196%.
OpenVPN remains one of the most widely supported protocols in the industry, prized for its maturity and ability to work almost anywhere. Its weakness has always been pacing, which is why many of the best VPN services now direct users to WireGuard by default.
OpenVPN DCO solves this problem. It moves the heavy lifting of encryption out of the application and into the deeper core of the operating system, reducing latency and easing CPU load without changing the security of the protocol.
IPVanish also changed its Windows OpenVPN encryption from AES-256-CBC to AES-256-GCM, a change it says reduces the time needed to connect to a server by 32%.
OpenVPN DCO remains exclusive for Windows users. As the provider confirms to TechRadar, “OpenVPN DCO is not possible on macOS, iOS or Android. Those operating systems have locked kernels.”
What IPvanish High Speed Mode Really Changes and How to Use It
Standard OpenVPN transfers data back and forth between the VPN application and the operating system. Each of these transfers costs time. Instead, DCO keeps the data channel closer to the Windows network layer, so encrypted traffic moves through the system with fewer stops.
IPVanish tested servers in New York, London, Berlin and Tokyo, three times a day for three consecutive days. On average, downloads improved by 131% on TCP and 196% on UDP, while uploads increased by 34% and 101% respectively.
“IPVanish is already known for delivering fast VPN speeds, and today we’re raising the bar for Windows OpenVPN,” said Subbu Sthanu, general manager of consumer cybersecurity at IPVanish, adding that streamers, gamers and remote workers should feel the difference.
You can activate the feature by updating your Windows app and accessing the OpenVPN protocol in the Settings tab.
One problem is that high-speed mode is not compatible with OpenVPN Scramble, IPVanish’s obfuscation feature that disguises your VPN traffic to bypass networks that block it. Turn on one and you will lose the other. For anyone connecting from a school, office, or VPN-filtering country, Scramble is probably the most important feature.
What other VPNs offer OpenVPN DCO?
ExpressVPN was one of the first providers to introduce OpenVPN DCO in March 2025, claiming a 2,000% increase in UDP performance. Windscribe also added DCO on Windows at the same time and recently extended it to Linux as well.
Norton VPN followed in September 2025, citing doubled speeds and 15% lower latency.
Surfshark, NordVPN, and PrivadoVPN also include a DCO adapter in their Windows clients. It’s still a short list, and most vendors are betting on WireGuard.
