Is Matrix / Element safe to use?

Matrix/Element is a solidly safe choice for message content, with caveats that are about architecture rather than the crypto. Conversations are end-to-end encrypted with the Olm/Megolm ratchets (the modern Rust 'vodozemac' implementation), and Element / Element X encrypt new direct messages by default and pre-select encryption when you create a private room — but encryption is per-room, so unencrypted and large public rooms exist and a room can't be retroactively encrypted. The cryptography has genuine audit pedigree (NCC Group 2016, Least Authority 2022) and academic formal analysis; in September 2022 researchers disclosed practically-exploitable flaws in Element's SDKs that were patched at disclosure, and in February 2026 a researcher flagged a missing all-zero-key check in vodozemac that Matrix acknowledged, disputed as practically exploitable (its threat model verifies signed keys before use), and is patching — all evidence that the project is actively scrutinised and responsive. The real privacy tradeoff is metadata and architecture: you hold an account on a homeserver (a federated @user:server identity, often requiring an email to register on matrix.org), and that homeserver — and every other homeserver in a federated room — can see room membership, device IDs, timestamps and reactions. There is no post-quantum cryptography in the message layer yet (only a spec discussion), no Tor-by-default, and no on-device duress protection. Bottom line: Matrix is private and trustworthy for message content and is one of the most credible open, federated options — but it leaks substantially more metadata than a serverless design and is not built for IP-level anonymity.