My app took 27 seconds to display the first page

I am trying to develop mobile application using ionic 2 angular2 and typescript. i run the app on google chrome with the line command: ionic serve. the app run perfectly.
so i said let’s run the app on android emulator. it tooks 27 seconds to open the login page. also some features hase some delay. and i don’t have android device to more test.
is this a normal behavior ?
what should i do ?
thank you in advance

Emulators are generally really really slow… try on real device…