[krainboltgreene]

They are not different. They can both help developers write in confidence and integrity. Babel can do more.

[alvis]

Babel can't do type checking, right?

[krainboltgreene]

It absolutely can! That said, the way it currently works is that babel-preset-flow and babel-preset-typescript both remove type annotations for the final build, essentially enabling flow or typescript to work without having to also be build engines.