ProtonVPN Windows Client v4.2.0: Smart Routing and Dark Mode

Lead: On September 12, 2026, ProtonVPN pushed client version v4.2.0 to Windows users. The update adds split tunneling and dark mode, and optimizes the WireGuard connection flow. For users who value efficiency and interface polish, this is a version worth upgrading to immediately.

Over the past year the Windows client has shipped roughly monthly minor releases. The v4.1 series focused on stability and compatibility, while v4.2.0 returns to feature parity — split tunneling and dark mode were the two most requested items in the community.

1. Split tunneling: route traffic your way

Split tunneling solves an old problem: not all traffic needs the encrypted tunnel. Local banking apps, intranet printers, or latency-sensitive games can suffer when forced through a VPN. v4.2.0 lets you choose per-app or per-IP which traffic goes direct and which goes through the tunnel, via Settings > Advanced.

You can keep ProtonVPN high-speed nodes for overseas services while local sites stay direct, balancing speed and availability. Compared to the previous global mode, split tunneling reduces latency and avoids unnecessary bandwidth use.

2. Dark mode: comfortable at night

Dark mode is more than inverted colors. v4.2.0 redesigned the low-light palette with high-contrast text on deep blue-gray backgrounds, avoiding the "halo effect" of pure black. For long night sessions, it noticeably reduces eye strain.

It also follows the system theme automatically — when Windows switches to its dark theme, the ProtonVPN client follows, no manual toggling needed.

3. Performance and benchmarks

Beyond features, v4.2.0 optimizes the WireGuard flow. The release notes mention improved handshake caching and route-table refresh, further cutting setup time.

Real case: Mark, a product manager in Beijing, was among the first batch. He whitelisted his video-call app for direct connection and routed the rest through the VPN. "Meeting latency dropped from 90 ms to 45 ms — no more praying during calls," he said.

4. How to upgrade

Existing users can click "Check for updates" under Settings > About. New users can get the latest installer from the free VPN download page. Upgrading preserves your configuration and subscription.

From split tunneling to dark mode to low-level optimizations, v4.2.0 balances features and experience, making the Windows client of Proton VPN more usable than ever. If you have not upgraded yet, it takes only a few minutes.