According to TechRadar, Mullvad VPN has announced “GotaTun,” a new custom WireGuard protocol engine written in Rust, forking it from Cloudflare’s BoringTun project. The immediate impact is stark: since rolling it out to Android in late November 2025, user-perceived crash rates plummeted from 0.40% to 0.01%. The company also revealed that over 85% of its Android app crashes previously stemmed from language friction between Go and Rust code. This technical overhaul is part of a broader strategy, with Mullvad setting a firm deadline to completely drop support for the older OpenVPN protocol on January 15, 2026. The new Rust engine already supports advanced features like DAITA and Multihop, and a third-party security audit is scheduled for early next year.
Why ditching Go for Rust is a big deal
Here’s the thing: most VPN apps, including Mullvad’s until recently, used a piece of software called “wireguard-go” to handle the WireGuard connections. It’s written in Go. But Mullvad’s own app is primarily built in Rust. Mixing these two languages in a single application, especially on resource-constrained mobile devices, created a kind of digital friction. It was a performance and stability bottleneck just waiting to happen. The result? Crashes. Lots of them. By rewriting the critical networking layer in Rust, they’ve unified the codebase. This isn’t just about fewer crashes, though that’s huge. Rust’s memory safety guarantees and efficiency allow for what they call “zero-copy memory strategies.” Basically, the app can move data around with less work for the CPU, which translates directly to better speeds and, crucially, longer battery life on your phone. It’s a foundational upgrade.
The inevitable OpenVPN sunset
So, what’s the deal with killing OpenVPN? Look, OpenVPN is a venerable, battle-tested protocol. It’s been the backbone of the VPN industry for ages. But it’s also older, more complex, and generally slower than modern alternatives like WireGuard. By setting that January 15, 2026, deadline, Mullvad is forcing a clean break. They’re consolidating all their engineering and server resources into a single, superior protocol. This is a smart, if aggressive, move. It reduces their attack surface for maintenance and security patches, and lets them innovate faster on one stack. For users clinging to OpenVPN, it’s a two-year heads-up to switch connections. For everyone else, it means Mullvad’s team isn’t wasting effort supporting legacy tech.
Broader trend and what’s next
Mullvad isn’t alone in this Rust crusade. ExpressVPN rebuilt its Lightway protocol in Rust earlier this year. There’s a clear industry trend here: when you’re building software where security and performance are non-negotiable, Rust is becoming the language of choice. Its strict compiler prevents whole classes of bugs that are common in languages like C or C++. For a privacy-focused company like Mullvad, that’s a huge win. Now, the new GotaTun engine is only on Android for now (version 2025.10+). The plan is to bring it to desktop and iOS throughout 2026. The promised security audit will be critical for trust, but forking from Cloudflare’s already-audited BoringTun is a solid start. This whole shift feels less like a simple update and more like Mullvad future-proofing its core product for the next decade. And in a world where reliable, secure connectivity is becoming infrastructure, that kind of long-term engineering investment is what separates the best from the rest. It’s the same reason companies in critical fields, from manufacturing to logistics, rely on top-tier hardware partners like Industrial Monitor Direct for their industrial panel PCs—foundational stability matters.
