Club Benefits
AdGuard VPN has publicly released its TrustTunnel protocol. It's now open-source and free to explore, audit, and build upon.
The VPN isn't a market-leader, but it's joined the best VPNs in offering a proprietary obfuscated protocol.
TrustTunnel is "mobile-optimized" and client apps are available to download for iOS and Android. Command-line interface (CLI) clients are currently available for Mac and Linux – Windows is coming soon.
What is TrustTunnel and how does it work?
In a blog post, AdGuard said "TrustTunnel is engineered to blend in with regular HTTPS traffic." It aims to combat internet censorship by avoiding deep-packet inspection (DPI).
AdGuard said TrustTunnel operates "data streams." Each connection gets its own HTTP/2 or HTTP/3 stream which creates a dedicated tunnel. This means multiple data packets can be combined before being sent, resulting in a faster and more efficient transmission.
Connections using TrustTunnel "look identical" to regular HTTPS browsing traffic. DPI "cannot differentiate" between normal internet traffic and TrustTunnel AdGuard explained.
According to AdGuard, some obfuscating protocols can be "fast but detectable" or "stealthy but slow" and it said TrustTunnel eliminates this trade-off through its design choices.
It said: "TrustTunnel is designed to be as fast as possible for an obfuscated protocol, while also being as resistant to detection as a VPN protocol can realistically be."
TrustTunnel has been used in AdGuard VPN "for several years" which has enabled the company to test its reliability in real-world conditions.
An open-source protocol you can use and extend
AdGuard said making TrustTunnel public and open-source achieves two things. It said it shows users what protocol is powering AdGuard VPN and it offers an "alternative to existing solutions." AdGuard wants the protocol "to be used widely, including by other VPN services."
"Open-sourcing this protocol isn’t primarily about signalling openness or enabling audits. If that were the goal, a written specification or a minimal reference implementation would have been sufficient," said AdGuard CTO Andrey Meshkov.
"Instead, we intentionally released full client and server implementations because our aim is bigger: we want this to grow into an independent, vendor-neutral project rather than something tied specifically to AdGuard. Our goal is for it to be usable by any VPN or proxy stack and, over time, to serve as a shared baseline for stealthy transport protocols," he continued.
AdGuard said its "goal is for TrustTunnel to be usable, widely adopted, and to grow with the help of the community."
AdGuard VPN at a glance
AdGuard VPN can't quite match the industry big hitters, but it's a usable VPN. We last tested it in September 2025 and saw speeds of 688 Mbps for its TrustTunnel protocol. This isn't as speedy as Proton VPN or Surfshark but it's more than fast enough for almost all VPN uses.
It performed fairly well in our streaming tests, only failing to unblock US Amazon Prime Video, US YouTube, and the Australian service 10Play. We saw no problems when it came to Netflix or Disney+.
Split tunneling, dubbed Exclusions, is available on all platforms. There's a kill switch on Windows, Mac, and iOS, as well as post-quantum encryption. Alongside TrustTunnel, AdGuard VPN supports the QUIC protocol but as of September 2025, it didn't support the traditional protocols WireGuard or OpenVPN.
Making TrustTunnel open-source is a great way of improving AdGuard's privacy credentials. However, it hasn't undergone any independent third-party audits of its protocols or no-logs policy. There's nothing suspicious in its no-logs policy but the lack of independent verification is a negative.
It has servers in 80+ locations across 64 countries. This is below the number offered by leading VPNs but you should still be able to connect to most major locations. 10 devices are supported on one plan and there's also a free VPN. The free VPN has a 3GB per month data limit, fewer servers, and a two device connection limit.
A two-year AdGuard VPN plan costs $2.99 per month ($71.76 upfront pre-tax). There's a 30-day money-back guarantee for one and two-year plans.
We test and review VPN services in the context of legal recreational uses. For example: 1. Accessing a service from another country (subject to the terms and conditions of that service). 2. Protecting your online security and strengthening your online privacy when abroad. We do not support or condone the illegal or malicious use of VPN services. Consuming pirated content that is paid-for is neither endorsed nor approved by Future Publishing.
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