ReferenceError: fetch is not defined

ReferenceError: fetch is not defined in Node.js

Does your log look something like this?

const res = await fetch("https://nodejs.org/api/documentation.json", {
            ^
ReferenceError: fetch is not defined

You might see this issue often if you are running on an older version of Node.js. fetch came to Node.js v17 under experimental flag --experimental-fetch. In Node.js v18, the experimental fetch API is available on the global scope by default. The implementation is based upon undici, an HTTP/1.1 client written for Node.js by contributors to the project.

const res = await fetch('https://nodejs.org/api/documentation.json');
if (res.ok) {
  const data = await res.json();
  console.log(data);
}

Through this addition, the following globals are made available: fetch, FormData, Headers, Request, Response.

Disable this API with the --no-experimental-fetch command-line flag.