Open Source VPN Apps for Android

Why Open Source Matters for Android VPNs

Android VPN apps route all of your device's internet traffic through their code, which means they have access to everything you do online: the websites you visit, the data you send and receive, your DNS queries, and your real IP address. A closed-source VPN app asks you to trust the developer's privacy claims without any way to verify them. Open source apps allow security researchers, journalists, and privacy-conscious users to inspect the code and confirm that it does exactly what it claims, nothing more.

Several closed-source Android VPN apps have been found to contain tracking libraries, inject ads into browsing sessions, or leak user data to third parties. The Google Play Store's review process does not audit VPN app behavior in depth, so an app can pass store review while still containing code that undermines the user's privacy. Open source apps, particularly those available on F-Droid (an alternative app store that builds apps directly from source code), provide a significantly higher level of assurance.

Open source VPN apps also tend to be lighter, faster, and free of the bloatware that many commercial VPN apps include. Features like built-in ad blockers, speed tests, and server recommendation algorithms add complexity, increase the attack surface, and consume battery. The open source alternatives focus on doing one thing well: securing your network connection.

WireGuard for Android

The official WireGuard app for Android is available on both Google Play and F-Droid. It is developed by the WireGuard project team and provides a clean, minimal interface for managing WireGuard tunnels on your phone or tablet.

Configuration is straightforward. You can import a .conf file from your device's storage, scan a QR code generated by your VPN server, or create a tunnel manually by entering keys, endpoints, and allowed IPs directly in the app. The app generates key pairs automatically when creating a new tunnel, so you do not need a separate key generation tool on the device.

WireGuard's most significant advantage on Android is its performance and battery efficiency. Because WireGuard sessions reconnect almost instantly when the network changes, the protocol handles transitions between Wi-Fi and cellular seamlessly. There is no multi-second reconnection delay that leaves your traffic unprotected, which is a common problem with OpenVPN on mobile. Battery consumption is minimal because WireGuard only sends data when there is traffic to encrypt, and the protocol's efficient cryptographic design requires less CPU processing per packet than OpenVPN.

The app supports auto-activation rules that can turn the VPN on automatically when you connect to untrusted Wi-Fi networks and turn it off when you are on your home network. Split tunneling is controlled through the AllowedIPs setting in the configuration, where you can specify which traffic routes through the VPN and which uses the local connection directly.

WireGuard for Android is licensed under GPLv2 and requires Android 5.0 (Lollipop) or later. The source code is available on the WireGuard project's Git repository.

OpenVPN for Android

OpenVPN for Android (not to be confused with the commercial "OpenVPN Connect" app) is a fully open source OpenVPN client maintained by Arne Schwabe. It is the recommended OpenVPN client for Android users who want a transparent, community-maintained app without telemetry or commercial tracking.

The app supports all OpenVPN features including certificate-based authentication, username/password login, custom cipher selection, TCP and UDP modes, and proxy support. You can import .ovpn configuration files directly, and the app handles embedded certificates and inline key material. For enterprise users, this means the same configuration files used on desktop OpenVPN clients work on Android without modification.

OpenVPN's TCP mode is particularly valuable on Android because mobile devices frequently connect through restrictive Wi-Fi networks at hotels, airports, and coffee shops. These networks often block non-standard UDP traffic but allow TCP on port 443. By configuring your OpenVPN server to listen on TCP 443, you can connect from virtually any network. WireGuard cannot offer this fallback because it only supports UDP.

The trade-off is performance. OpenVPN on Android uses more CPU and battery than WireGuard, and reconnection after a network change takes several seconds during which traffic is either blocked (if the kill switch is active) or routes outside the tunnel (if it is not). For most browsing and messaging, the performance difference is not noticeable, but for video calls, streaming, or large file transfers, WireGuard provides a smoother experience.

OpenVPN for Android is available on Google Play and F-Droid. The source code is hosted on GitHub under the GPLv2 license.

ProtonVPN

ProtonVPN is developed by Proton AG, the Swiss company behind ProtonMail. While ProtonVPN is a commercial VPN service, all of its client applications, including the Android app, are fully open source and have undergone independent security audits. The company publishes audit reports publicly, and the Android app source code is available on GitHub.

ProtonVPN stands out for offering a genuinely usable free tier. Free users get access to servers in the Netherlands, Japan, and the United States with no data cap, no bandwidth limit, and no ads. The free tier is limited to a single simultaneous connection and does not include access to P2P-optimized or streaming-optimized servers, but it is sufficient for basic privacy protection. Paid plans add more server locations, higher speeds, and features like Secure Core (multi-hop routing through privacy-friendly jurisdictions) and NetShield ad and malware blocking.

The Android app supports both WireGuard and OpenVPN protocols, with WireGuard selected by default for its performance advantages. It includes a kill switch that blocks all traffic if the VPN connection drops, split tunneling to exclude specific apps from the tunnel, and a "Smart Protocol" feature that automatically switches between protocols and ports to find a connection that works through restrictive networks.

ProtonVPN's Swiss jurisdiction provides strong legal privacy protections, and the company has been subjected to multiple legal challenges that validated their no-log claims. The Android app is available on Google Play and F-Droid.

Calyx VPN

Calyx VPN is a completely free, community-funded VPN service operated by the Calyx Institute, a New York-based nonprofit focused on digital privacy. The app uses the Bitmask VPN client, which is open source and supports both OpenVPN and WireGuard protocols. There are no accounts, no registration, and no data caps. You install the app, tap connect, and your traffic routes through Calyx Institute's servers.

The simplicity is both the strength and the limitation of Calyx VPN. There is no server selection, the app connects to the nearest available server automatically. There is no split tunneling, no custom DNS, and no advanced configuration options. The service provides exactly one thing: a private, encrypted connection to the internet, funded by donations and grants rather than subscription fees.

Calyx VPN is a good choice for users who want basic VPN protection without creating any accounts or sharing any personal information. The Calyx Institute has a strong track record in digital rights advocacy and has never been found to log user activity.

Mullvad VPN

Mullvad is a Swedish VPN service known for its strict privacy practices. The company does not require an email address, name, or any personal information to create an account. Instead, you receive a randomly generated account number that serves as your only credential. Payment can be made anonymously through cryptocurrency or even by mailing cash to their office.

All Mullvad client applications, including the Android app, are open source and have been independently audited. The Android app supports both WireGuard and OpenVPN, with WireGuard as the default. Features include a kill switch, auto-connect on untrusted networks, split tunneling by app, custom DNS servers, and multihop routing through two VPN servers for additional privacy.

Mullvad charges a flat 5 euros per month with no contracts, discounts, or price tiers. The straightforward pricing reflects the company's no-nonsense approach to privacy: no affiliate programs, no influencer partnerships, and no data collection beyond what is technically necessary to operate the service. The Android app is available on Google Play, F-Droid, and as a direct APK download from Mullvad's website.

Orbot (Tor for Android)

Orbot is not strictly a VPN but deserves mention because it routes Android traffic through the Tor network, providing anonymity that no traditional VPN can match. While a VPN hides your traffic from your ISP and changes your apparent IP address, Tor routes your traffic through three independently operated relays, ensuring that no single party can link your identity to your browsing activity.

Orbot can function as an Android VPN service, routing all device traffic through Tor, or it can be configured as a SOCKS proxy for specific apps. The trade-off is performance: Tor adds significant latency (typically 200 to 500 milliseconds per hop) and limits throughput, making it unsuitable for streaming, video calls, or large downloads. For browsing, messaging, and reading, Tor provides the strongest available anonymity.

Orbot is developed by the Guardian Project, a collective of developers focused on mobile privacy tools. It is fully open source and available on Google Play, F-Droid, and direct download. Orbot works alongside a VPN: you can use a VPN for general traffic and route specific apps through Tor via Orbot for maximum privacy.

Choosing the Right App

For connecting to your own self-hosted VPN server, the official WireGuard app or OpenVPN for Android are the right choices depending on which protocol your server runs. For a managed VPN service with open source clients, ProtonVPN offers the best combination of free access, open source transparency, and feature completeness. For maximum simplicity with no accounts, Calyx VPN delivers basic protection with zero friction. For maximum privacy with a commercial service, Mullvad's anonymous account model is unmatched.