Fetch API vs XMLHttpRequest

Question

I know that Fetch API uses Promises and both of them allow you to do AJAX requests to a server.

I have read that Fetch API has some extra features, whic

Answer 1

The answers above are good and provide good insights, but I share the same opinion as shared in this google developers blog entry in that the main difference (from a practical perspective) is the convenience of the built-in promise returned from fetch

Instead of having to write code like this

function reqListener() {
    var data = JSON.parse(this.responseText);
}

function reqError(err) { ... }

var oReq = new XMLHttpRequest();
oReq.onload = reqListener;
oReq.onerror = reqError;
oReq.open('get', './api/some.json', true);
oReq.send();

we can clean things up and write something a little more concise and readable with promises and modern syntax

fetch('./api/some.json')
    .then((response) => {
        response.json().then((data) => { 
            ... 
        });
    })
    .catch((err) => { ... });