KeePassXC vs Proton Pass Comparison

• Pass Plus (individual, annual): $35.88/year
• Pass Family (up to 6 users, annual): $59.88/year

First-level security certification of KeePassXC 2.7.9 on Windows — full source-code review, penetration testing of every security function, and cryptographic and random-number-generator analysis

Source-code review and gray-box testing of the browser extensions, mobile and desktop apps, and CLI

The database is encrypted with AES-256 by default (Twofish and ChaCha20 are also selectable) in the KDBX 4 format, with an HMAC-SHA-256 integrity check that detects tampering. The master key is derived with Argon2d by default — a memory-hard function that resists GPU and ASIC cracking — with the older AES-KDF still available. The composite master key can combine a password, a key file, and a YubiKey or OnlyKey challenge-response secret.

Vault and item data are encrypted with 256-bit AES-GCM under 32-byte random keys; the user key is protected by a bcrypt hash of the account password. Authentication uses a hardened SRP implementation; sharing uses OpenPGP with ECC (Curve25519). Every field is encrypted client-side — usernames, URLs and notes included — so Proton cannot see which services you hold accounts with. Offline access on paid plans uses Argon2 for the local hash.

Volunteer, community-run open-source project under the keepassxreboot organization on GitHub — no company and no venture funding behind it. Development is paid for by donations. Forked from KeePassX in 2016; the KeePass lineage goes back to 2003.

Proton AG, Geneva, Switzerland. Since June 2024 the primary shareholder is the non-profit Proton Foundation, which the founders endowed with Proton shares in an arrangement they describe as irrevocable. Proton began as a 2014 crowdfunding campaign.