ProtonVPN vs Mullvad VPN Independent Audits and Port Forwarding Compared

Choosing a VPN often comes down to trusting a company with your data, and nothing builds trust like independent verification. If you're a power user who relies on features like port forwarding for activities like hosting game servers or maximizing torrenting speeds, your options narrow significantly. This comparison cuts through the marketing to analyze ProtonVPN and Mullvad VPN based on their real-world performance in independent audits and their implementation of the crucial port forwarding feature, giving you the facts needed to make an informed security decision.

What you’ll learn:

• How ProtonVPN and Mullvad's audit histories stack up against each other.
• The critical differences in their port forwarding functionality and security.
• Which service is the better fit for your specific privacy and technical needs.

Why Audits and Port Forwarding Matter for Your Privacy

In the VPN world, claims are cheap. Any provider can say they have a “no-logs policy,” but without proof, it's just words. Independent security audits are the gold standard for verification, where a third-party firm examines a provider's infrastructure and code to confirm their privacy claims are true. This is your best assurance that a VPN isn't secretly tracking you.

Alongside trust, you need functionality. Port forwarding is a prime example. It's a networking technique that allows incoming connections to reach your device through the VPN tunnel. For many, it's non-negotiable. It can drastically improve download speeds for peer-to-peer filesharing, enable you to host game or media servers, and allow remote access to your home network. However, not all port forwarding is created equal, and its implementation can have major privacy implications, which we'll explore in detail.

Head-to-Head: Independent Audit History

Let's break down how these two privacy-focused providers have opened themselves up to external scrutiny.

ProtonVPN Audits

Proton, the company behind ProtonVPN and Proton Mail, has built its reputation on transparency. ProtonVPN's infrastructure and “no-logs” policy were audited by the Swiss security firm SEC Consult in 2023. The audit confirmed that their servers do not store any identifying data and that their no-logs policy is technically enforced. Furthermore, Proton has open-sourced its applications, allowing anyone to review the code, and its apps undergo regular independent security audits. This consistent commitment to verification is a strong point in Proton's favor.

Mullvad VPN Audits

Mullvad takes a similarly rigorous, if not more frequent, approach to audits. The company has undergone multiple public infrastructure audits, with the most recent one conducted by the German-based Cure53 in 2024. This follows a prior Cure53 audit in 2020 and another in 2022. These repeated checks consistently verify Mullvad's no-logs policy and the overall security of its server infrastructure. Mullvad's dedication to recurring audits demonstrates an ongoing commitment to proving its trustworthiness, not just a one-time box-ticking exercise.

Audit Verdict

Both services are leaders in transparency, but Mullvad has a slight edge in frequency. While Proton's audits are thorough, Mullvad's pattern of repeated, recent audits by a highly respected firm like Cure53 shows a relentless focus on proving its security claims over time. You can't go wrong with either, but Mullvad's audit history is arguably the most robust in the commercial VPN industry. For more on how we evaluate security, see our VPN testing methodology.

The Port Forwarding Deep Dive

This is where the two services diverge significantly. While both offer port forwarding, their approaches reflect different philosophies on security and convenience.

How Mullvad Handles Port Forwarding

Mullvad offers a static, permanent port forwarding system. When you enable the feature in the app or on your account page, you are assigned a random port number (e.g., 54321) that is permanently tied to your account. This port remains open as long as you keep the feature active. The major advantage is consistency; you can set up a service once and know the port will never change. The potential downside is that this static port is linked to your account number. While Mullvad is a proven no-logs service, this creates a persistent identifier that could, in theory, be correlated with your activity if their no-logs policy were ever compromised.

How ProtonVPN Handles Port Forwarding

ProtonVPN takes a more dynamic and privacy-centric approach, which it calls “Forwarded Ports” or “Smart Routing.” Instead of a permanent port, ProtonVPN assigns a temporary, random port that is active only for the duration of a single VPN session. Once you disconnect from the VPN server, that specific port is closed and reassigned. The next time you connect, you'll get a new random port. This method enhances privacy by preventing a long-term identifier from being associated with your account. The trade-off is a lack of permanence; it's not suitable for hosting services that require a stable, unchanging public port.

Port Forwarding Verdict

Your choice here depends entirely on your use case and threat model.

• Choose Mullvad VPN if you need a stable port for long-term hosting (e.g., a game server, Plex server, or website). The convenience of a static port is unmatched for these tasks.
• Choose ProtonVPN if your primary concern is maximizing anonymity for peer-to-peer filesharing. The dynamic, session-based port forwarding severs the link between your activity and a permanent account identifier, offering a higher degree of privacy for torrenting.

Beyond Audits and Ports: Other Key Differences

While audits and port forwarding are critical, they aren't the whole story. Here’s a quick look at other distinguishing factors.

Jurisdiction and Payment Methods

Mullvad is based in Sweden, a member of the 14-Eyes intelligence alliance, but its no-logs policy has been proven through audits. It excels in anonymous payment options, accepting cash sent by post, Bitcoin, and Monero. Proton is based in privacy-friendly Switzerland and offers a generous free tier, but its anonymous payment options are more limited.

Server Networks and Features

ProtonVPN has a larger server network and offers specialized Secure Core servers that route your traffic through multiple countries for extra protection against network-based attacks. Mullvad maintains a strong, privacy-focused network and is renowned for its simple, effective apps and commitment to removing features that could potentially be used for tracking, like certain types of telemetry.

Final Recommendation: Which VPN Is Right for You?

Both ProtonVPN and Mullvad VPN are top-tier choices for the privacy-conscious user, but they cater to slightly different needs.

Go with Mullvad VPN if your priority is a proven, frequently audited no-logs policy and you require port forwarding for stable, long-term hosting. Its anonymous payment options are also a major win for those seeking maximum privacy.

Go with ProtonVPN if you value a dynamic, session-based port forwarding system for anonymous torrenting, want access to a free tier, or need advanced security features like Secure Core servers. Its Swiss jurisdiction is also a strong privacy advantage.

Ultimately, the “better” VPN is the one that aligns with your specific technical requirements and personal privacy standards. By focusing on the verified evidence from independent audits and understanding the critical trade-offs in their port forwarding implementations, you can move beyond marketing and choose the tool that truly protects your digital life. Don't just take their word for it—choose a VPN that proves its worth.

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