What is the significance of browserslist in package.json created by create-react-app

create-react-app package.json
Tanzeel picture Tanzeel · Apr 4, 2019 · Viewed 10.5k times · Source

I was asked this in an interview. I could not answer.

"browserslist": [
">0.2%",
"not dead",
"not ie <= 11",
"not op_mini all"
]

I can see that Its an array. "not ie <=11" means will not run on lower than Internet Explorer v11 "op_mini" must be related to Opera mini.

But I want to know why it is required.

Answer

Fernando Souza picture Fernando Souza · May 12, 2019

That's a React configuration option to know which browsers the build process should target to.

As the documentation says:

The browserslist configuration controls the outputted JavaScript so that the emitted code will be compatible with the browsers specified.

If you are intend to use a ES feature make sure all browsers specified supports it, otherwise you have to include polyfills manually. React will not do it for you automatically.

See more in: https://facebook.github.io/create-react-app/docs/supported-browsers-features and https://create-react-app.dev/docs/supported-browsers-features/

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