Browser TLS checker

See the TLS version, cipher and key exchange this browser negotiated with PQC Toolbox.

CLIENT CONNECTION

This browser → PQC Toolbox

Toolbox reads the TLS settings for the connection carrying this browser’s request to this site. The browser can reuse an open connection or establish a new one.

Negotiated session

Ready to check.

Does my browser use post-quantum TLS?

Look at the negotiated key exchange for this connection. A group such as X25519MLKEM768 shows that your browser and this server agreed to use hybrid post-quantum key exchange. A hybrid group appearing only in the browser’s offer establishes support, not selection.

The browser offers algorithms. The server chooses compatible settings. A hybrid group combines classical key exchange with ML-KEM to help protect captured traffic against future quantum decryption. A classical group uses traditional public-key cryptography. A different server can make a different choice.

The traffic cipher encrypts the data once keys are established. Certificate authentication is a separate question. This test measures key exchange and traffic protection for the connection reaching this listener.