Flutter global font size multiplier

Android and iOS both have a system setting to make texts bigger or smaller in general. Flutter takes it into account. It uses it by default.

Get the value “textScaleFactor” using MediaQuery

MediaQuery.of(context).textScaleFactor

https://api.flutter.dev/flutter/widgets/MediaQuery-class.html

In case if you want to turn this mechanism off, or change scaling value for a part of your app, wrap it in your own MediaQuery object.

Widget build(BuildContext context) {
  double myOwnScaleFactor = 1.0;
  return MediaQuery(
    child: Container(), // your app, or part of it
    data: MediaQuery.of(context).copyWith(textScaleFactor: myOwnScaleFactor),
  );
}