There's more...

Note that your browser needs to support the Server Push feature; otherwise, your page will work as usual. So, make sure you check that PushBuilder is null before using it and ensure all users will have the working application.

JSF 2.3 is built on top of the Server Push feature, so if you just migrate your JSF application to a Jakarta EE 8-compatible server, you get its performance boost for free!

Finally, Server Push only works under a Secure Sockets Layer (SSL) protocol, so pay attention to it.