Polyfills

The Runtime Edge is built on top of Web APIs available in Node.js.

The minimum Node.js version supported is v14.6.0 that is mapped to ES2019.

Under the hood, the following Web APIs are used by the Runtime Edge:

polyfill	node14	node16	node18
util.types (opens in a new tab)	x
WebCrypto (opens in a new tab)	x
AbortController, AbortSignal, DOMException (opens in a new tab)	x
base64 (opens in a new tab)	x
fetch, Request, Response (opens in a new tab)	x	x
URLPattern (opens in a new tab)	x	x	x
WebStreams (opens in a new tab)	x	x	x

The Runtime Edge polyfills missing APIs for backward compatibility with older Node.js versions.

In the future, Node.js will become a superset of the Runtime Edge with built-in support for the available APIs.