Missing polyfills
- ES
BigInt can't be polyfilled since it requires changes in the behavior of operators, you can find more info here. You could try to use JSBI.
- ES
Proxy can't be polyfilled, you can try to use proxy-polyfill which provides a very small subset of features.
- ES
String#normalize is not a very useful feature, but this polyfill will be very large. If you need it, you can use unorm.
- ECMA-402
Intl is missing because of its size. You can use these polyfills.
- ES
Temporal is missing because of its size. You can use temporal-polyfill or @js-temporal/polyfill.
fetch is not polyfilled: it depends on the networking of the platform, and now it's natively available in all modern browsers, Node.js 18+, Deno and Bun. For legacy engines, you can use, for example, this polyfill.
- ES
WeakRef and FinalizationRegistry can't be polyfilled since they require integration with the garbage collector.
- ES
SharedArrayBuffer and Atomics can't be polyfilled since they require memory shared between threads.
- ES resizable
ArrayBuffer, growable SharedArrayBuffer and Float16Array are not polyfilled. Math.f16round and DataView methods for float16 values are polyfilled.
- Some new ES
RegExp syntax, like lookbehind assertions or d and v flags, is not polyfilled.