AFAIK, Chrome "certificate pinning" may not exactly be what you think "certificate pinning" means. It should be more precisely called "certificate authority pin

AFAIK, Chrome "certificate pinning" may not exactly be what you think "certificate pinning" means. It should be more precisely called "certificate authority pinning". What it means is that Chrome will not trust certs for Google properties except those issued by certain certificate authorities. Reference: https://www.imperialviolet.org/2011/05/04/pinning.html https://www.imperialviolet.org/2011/05/04/pinning.html Unless things changed since I last checked. In contrast, "real" "certificate pinning" as done in some mobile apps (IIRC Twitter) involves storing the hash of the certificate itself in the app. No other certificate, even from the same CA, will be accepted.