[Perf] Optimize the size of the lib and make the library modular

[JosefJezek]

Could you optimize the size of the lib? We have limit ~ 50 KB per route on 3G mobile networks. :-/

Check out the video Measure Time to Interactive.

The Cost Of JavaScript is high.

• 178.4 KB / gz 53.6 KB https://cdn.jsdelivr.net/npm/firebaseui@2.5.1/dist/npm.min.js

[bojeil-google]

If you are using a subset of the supported providers, you can recompile with some js compiler that supports dead code removal. For example, if you are not using phone authentication, this would cut the size of the library significantly.
Currently, size optimization is not a top priority especially since we have many additional new and requested features to add to our library.

[JosefJezek]

@bojeil-google @nicolasgarnier Could you make this library modular? Modul per provider?

[JosefJezek]

Any progress? Firebase SDK libs and UI lib are bad solution for PWA now. :-( Perf and libs size are critical for Lighthouse score.

[codeofsumit]

Would be great if firebaseUI could be modularized. I'm using it in many production apps (love it) but the size is a constant drawback, especially as I only use 2 or 3 providers.
In any case, keep up the good work 👍

[bojeil-google]

There are ongoing discussions to modularize the core JS SDK. Once that materializes (it's quite an effort), we can look into FirebaseUI modularization.