The answer, up front
Yes, Google Chrome supports post-quantum cryptography. It negotiates the hybrid key exchange X25519MLKEM768 by default for TLS 1.3 and QUIC connections, which combines the classical X25519 algorithm with the NIST standard ML-KEM. When a server also supports it, the connection is already protected against the harvest-now-decrypt-later threat for key establishment, with no setting to enable 1, 2.
Last verified: Oct. 2, 2026.
What Chrome protects today
Chrome began shipping a hybrid post-quantum key exchange in 2023 (as X25519Kyber768) and switched to the finalized X25519MLKEM768 group, enabled by default on desktop, from version 124 in April 2024 1. The design is deliberately hybrid: the browser and server derive shared secret material from both X25519 and ML-KEM and combine them, so the connection stays secure as long as either component holds. That keeps the well-studied classical exchange while adding lattice-based protection against a future quantum attacker 2.
The practical effect is large. By early 2026, a substantial and rising share of browser-initiated TLS 1.3 handshakes carried an X25519MLKEM768 key share, because both Chrome and the major content delivery networks prefer it when both ends support it.
What Chrome does not do yet
Supporting a post-quantum key exchange protects confidentiality, not authentication. The certificates that prove a server's identity still use classical signatures such as RSA and ECDSA. Post-quantum signatures are much larger, so dropping them into traditional X.509 certificates would bloat every handshake 3.
Google's answer is not to put post-quantum signatures into the current certificate format. Chrome has no immediate plan to add post-quantum X.509 certificates to its root store, and is instead helping develop Merkle Tree Certificates (MTCs) through the IETF to keep the authentication side efficient as it migrates 3. So the key-exchange half of the browser migration is well underway, and the signature half is still being designed.
What this means for your organization
Browser support is only one surface. Chrome protecting a user's connection does nothing for the quantum-vulnerable cryptography inside your own applications, APIs, VPNs, internal services, firmware, and stored data. The browser result is a useful signal that the transition is real and already shipping, not a reason to treat your own estate as covered. The work that matters for you is the same as ever: find where quantum-vulnerable cryptography lives, prioritize it, and migrate key establishment first.