Top 5 Free Open Source VPNs for Windows (2025): Ranked by Users & Reviews

Introduction

In an era of increasing online surveillance and geo-blocked content, VPNs have become essential tools for internet privacy. But many users are hesitant to pay for premium services or download apps with hidden costs.

That’s where free open-source VPNs come in. They offer transparency, control, and often robust security—at zero cost.

In this blog, we explore the top 5 open-source VPNs for Windows in 2025, ranked by user reviews, community trust, and real-world use cases.

1. Proton VPN (Free Plan)

Why It’s Ranked #1:
Proton VPN remains the most recommended free VPN due to its no-logs policy, unlimited bandwidth, and audited open-source code.

Key Features:

• Unlimited data (even on free plan)

• Strict no-logs policy

• Based in Switzerland (strong privacy laws)

• Easy Windows app with kill switch and DNS leak protection

• Fully open-source and regularly audited

Limitations:

• Only 3 free server countries (US, Japan, Netherlands)

• Slower speed on free tier

Best For: Everyday users who want an easy, privacy-respecting VPN without limits.

2. SoftEther VPN

Why It’s Ranked #2:
SoftEther is a highly versatile and powerful VPN project with support for multiple protocols, often favored by universities and developers.

Key Features:

• Multi-protocol (SSL-VPN, L2TP, IPsec, OpenVPN)

• Open-source and actively maintained

• Strong firewall bypass capabilities

• Great performance even on limited hardware

Limitations:

• Setup requires technical knowledge

• You must host or connect to a server

Best For: Advanced users who want full control over configuration and protocols.

3. OpenVPN

Why It’s Ranked #3:
OpenVPN is the backbone of many commercial VPNs. It’s open-source, reliable, and highly configurable.

Key Features:

• Uses industry-standard OpenVPN protocol

• Excellent community and documentation

• Supports TCP/UDP for flexible connections

• Secure encryption (AES-256)

Limitations:

• Not plug-and-play; needs manual configuration

• Requires access to a VPN server (self-hosted or third-party)

Best For: Users who already have or want to set up their own VPN server.

4. Outline VPN

Why It’s Ranked #4:
Created by Jigsaw (a Google initiative), Outline VPN focuses on simplicity and user-friendly setup, even for non-tech users.

Key Features:

• Super simple GUI-based setup

• Based on Shadowsocks (proxy-like VPN)

• Self-hosted for full data control

• Easy sharing of access keys

Limitations:

• Not a full system VPN (protects only selected apps)

• Limited anonymity vs full VPNs

Best For: Small teams or journalists needing fast, self-hosted proxy-like VPNs.

5. n2n VPN

Why It’s Ranked #5:
n2n is unique in that it builds peer-to-peer VPN tunnels across systems, even behind NAT. Great for local/private use.

Key Features:

• Peer-to-peer encrypted networking

• No central VPN server needed

• Works on Windows, Linux, macOS

• Ideal for file sharing or LAN expansion

Limitations:

• Not designed for general online anonymity

• Requires technical knowledge

• Less mainstream support

Best For: Developers or local teams needing LAN-style encrypted communication.

Comparison Chart: Open-Source VPNs for Windows (2025)

Final Verdict: Best to Least for General Users

1. Proton VPN – Best all-round free VPN for privacy and ease of use

2. SoftEther VPN – Advanced and flexible, but technical

3. OpenVPN – Reliable and secure, but needs a server

4. Outline VPN – Great for proxy-style tunnels

5. n2n VPN – Niche tool for private networking

Conclusion

Whether you’re a student, freelancer, or developer, these open-source VPNs offer a secure, free way to protect your data. While no VPN is perfect, each of the tools listed above serves a specific need—from full anonymity to P2P LAN access.

Remember: while free VPNs are helpful, choosing open-source means you also get transparency and community-driven security updates.