Why do JA3 fingerprints change?

Starting with Chrome version 110, the Client Hello permutation was introduced, meaning the order of extensions is now randomized. As a result, JA3 fingerprints will also be randomized. Therefore, when comparing the JA3 fingerprints of FLClient and a browser, they may differ (with the exception of specific versions of Safari or Firefox). However, this doesn't mean that TLS fingerprints aren't a concern. The order of ClientHello extensions is just one of the factors servers use to identify automated requests from actual browsers. If you have any issues with fingerprints or would simply like to add a new personalized Client Hello, please let me know in the support channel.

• Jonathan Foote. (February 8, 2023). Examining Chrome's TLS ClientHello Permutation. Fastly. Link