ProtonVPN

Who ProtonVPN is, in one paragraph

ProtonVPN is one of several products from Proton AG, the Geneva-based company best known for Proton Mail. Proton was founded in 2014 by a group of CERN researchers around Andy Yen, originally to provide end-to-end encrypted email after the Snowden disclosures, and added VPN service in 2017 to cover the network layer that mail alone could not protect. In June 2024, Proton AG transferred majority ownership to a newly chartered Swiss non-profit, the Proton Foundation, giving the company a unique corporate structure among major VPN providers — neither pure for-profit (Nord) nor a small private partnership (Mullvad), but an audited stiftung whose charter legally constrains it from selling user data or being acquired without foundation consent. Engineering happens in Geneva, Prague and Skopje; legal entity is purely Swiss.

Backend architecture & engineering

ProtonVPN runs three meaningful protocols: WireGuard (default), OpenVPN (legacy compatibility) and Stealth — Proton's in-house obfuscation that wraps WireGuard inside a TLS connection so it looks indistinguishable from ordinary HTTPS to a packet inspector. Stealth is the protocol Proton recommends from networks in Iran, Russia and Myanmar, and it's a meaningfully different approach to obfuscation than Nord's modified OpenVPN servers or Mullvad's Shadowsocks bridge.

The signature feature is Secure Core: a Proton-owned, hardened-datacenter network in Switzerland, Iceland and Sweden that every Secure Core session routes through before it exits to its final country. The intent is that an attacker who compromises the exit server in, say, Hong Kong, still cannot link the egress traffic back to the user — because the user's real IP only ever reached the Secure Core node, not the exit.

The Secure Core fleet is owned by Proton, not rented — the Swiss nodes famously live in a former military bunker beneath 1,000 metres of granite in the Swiss Alps. That's marketing-friendly, but the real engineering point is that Proton operates the physical layer on those nodes and therefore controls boot integrity, disk encryption and hardware tampering checks at every Secure Core hop. The regular exit fleet is mixed (some owned, some rented), but all servers are full-disk-encrypted bare metal, and Proton is publicly committed to a transition to fully stateless ("Proton stateless servers") which was complete on the WireGuard fleet by mid-2024.

Traffic monitoring, encryption & network privacy

Proton uses WireGuard's standard suite — ChaCha20-Poly1305, Curve25519, BLAKE2s — and on OpenVPN profiles ships AES-256-GCM with SHA-512 HMAC and a 4096-bit DH group (a step above Nord's 2048-bit). In late 2024, Proton enabled an experimental ML-KEM-768 post-quantum hybrid on a subset of servers — built on the NIST PQC finalist standard — which Mullvad also offers in preview and which Nord does not yet. Practically, post-quantum hybrids matter less for stream confidentiality today and more for resistance to harvest-now-decrypt-later attacks; you should turn it on if you expect long-lived adversarial archives of your traffic.

DNS is handled by Proton's own resolvers, on the same machine that terminates your WireGuard tunnel — so no third party sees the metadata, but Proton itself sees the queries. The clients run NetShield, a DNS-filter feature comparable to Nord's Threat Protection. Optional in the free tier, on by default on paid plans.

Legal compliance, jurisdiction & law-enforcement interaction

Switzerland is a deliberately chosen jurisdiction. It is outside the 5/9/14-Eyes alliances, has a constitutional right to privacy (Article 13), and — critically for VPN operators — has no mandatory data-retention law that applies to VPN providers in the way that, for instance, the UK's IPA 2016 or Australia's TIA Act apply. Swiss law does permit narrow targeted compulsion via the Federal Act on the Surveillance of Postal and Telecommunications Traffic (BÜPF), but the threshold and judicial oversight are high, and Proton's published transparency reports show that ProtonVPN has historically not been compelled to log a specific user (Proton Mail has, in narrow Swiss criminal cases — those decisions are reported in detail).

The reason this matters in practice is that Proton publishes the specifics — case numbers, what data was produced (usually none for VPN), and what was contested. NordVPN's Panama reports are credible but less verifiable; Mullvad's reports are similarly detailed but pertain to a Swedish jurisdiction that is inside 14-Eyes. If a court order is your specific worry, ProtonVPN's posture is the strongest of the three.

Data breaches, history of leaks & incident response

ProtonVPN has never had a server-compromise incident comparable to NordVPN's 2018 Finland breach. The most cited incident in Proton's history is the 2021 Proton Mail / French climate activist case, in which Proton was compelled by Swiss authorities (acting on a French request via mutual legal assistance) to log the recovery email address for a specific Proton Mail account. The case has nothing to do with ProtonVPN — and Proton publicly used it to lobby for clearer Swiss law on what providers can and cannot be compelled to log — but it is the one case where the public learned exactly what Proton can be made to do under Swiss process. The answer was: account-creation metadata for a specifically named, targeted account, on a Mail product, never bulk and never on VPN.

Proton runs a HackerOne bug bounty since 2017, has paid out roughly $400,000 cumulatively, and discloses incidents on its security blog within seven days when material. Compared to Nord's October-2019 disclosure of a March-2018 breach, that is a meaningfully better track record on incident communications.

VPN origin & company transparency

The 2024 transition to Proton Foundation control is the most important transparency change in any VPN provider in years. Foundation control means:

• Proton AG cannot be acquired by another for-profit company without Foundation consent.
• The Foundation's charter, filed in the Geneva canton commercial register, explicitly prohibits selling user data.
• Financial statements are publicly auditable under Swiss foundation law.
• Leadership succession is bound by the Foundation's privacy mission, not shareholder pressure.

No other mainstream VPN has this structure. NordVPN's VC-backed for-profit posture and Mullvad's small private partnership both create different (and not necessarily worse) incentive structures, but neither is bound to a charter the way Proton now is.

Performance & reliability

ProtonVPN's standard WireGuard throughput sits at 450–700 Mbps on a 1 Gbps line to a same-continent server — slower than NordVPN's NordLynx (650–900 Mbps) on identical hardware, and roughly comparable to Mullvad (500–750 Mbps). The reason is Proton's userspace WireGuard implementation prioritises correctness and audit-friendliness over raw kernel-level performance; on Linux you can install wireguard-tools directly and recover most of the gap.

Secure Core comes with a measured 30–50% throughput penalty (Geneva→New York via Iceland is meaningfully slower than direct), which is the engineering cost of the extra hop. The free tier is the best free VPN service on the market — usable, no data cap, but throttled to roughly 10 Mbps and limited to five country exits. It is genuinely sufficient for general browsing and email.

Streaming unblock is patchier than Nord's: Plus-plan customers get reliable Netflix US/UK and BBC iPlayer, but Plus-plan IP pools are smaller, and Mullvad refuses to play this game at all.

How ProtonVPN stacks up against NordVPN & Mullvad

Pros & cons

Verdict