- IPVanish added OpenVPN Data Channel Offload (DCO) to its Windows app
- Internal testing recorded download increases of up to 196%
- The function 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 the feature boosts OpenVPN download speeds by up to 196%.
OpenVPN remains one of the most supported protocols in the industry, valued for its maturity and its ability to work almost anywhere. Its weakness has always been speed, which is why so many of the best VPN services now steer users towards WireGuard by default.
OpenVPN DCO solves this problem. It moves the heavy lifting of encryption out of the app and into the deepest core of the operating system, reducing latency and lightening the CPU load without changing the security of the protocol.
IPVanish has also switched its Windows OpenVPN cipher from AES-256-CBC to AES-256-GCM, a change it says cuts 32% of the time needed to connect to a server.
OpenVPN DCO remains exclusive to Windows users. As the provider confirms to TechRadar, “OpenVPN DCO is not possible on macOS, iOS or Android. These operating systems have locked kernels.”
What IPvanish’s high-speed mode actually changes and how to use it
Standard OpenVPN moves data back and forth between the VPN app and the operating system. Each and every one of these handovers costs time. DCO instead 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 offering fast VPN speeds, and today we’re raising the bar for Windows OpenVPN,” said Subbu Sthanu, General Manager, Consumer Cybersecurity at IPVanish, adding that streamers, gamers and telecommuters should all feel the difference.
You can turn the feature on by updating your Windows app and going to the OpenVPN protocol in the Settings tab.
One catch is that high-speed mode isn’t compatible with OpenVPN Scramble — IPVanish’s obfuscation feature that disguises your VPN traffic to slip past networks that block it. Turn one on and you lose the other. For anyone connecting from a school, office, or country that filters VPNs, Scramble is probably the most important feature.
What other VPNs offer OpenVPN DCO
ExpressVPN was among the first providers to unveil OpenVPN DCO in March 2025, claiming a 2,000% jump in UDP performance. Windscribe also added DCO on Windows at the same time and recently extended it to Linux as well.
Norton VPN followed suit in September 2025, citing doubled speeds and 15% lower latency.
Surfshark, NordVPN, and PrivadoVPN also all ship a DCO adapter in their Windows clients. It’s still a short list, with most providers betting on WireGuard instead.
