AJAX request success in JavaScript

The ok property contains true if a server responded with HTTP status from the 2xx group, and false if from another group:

button.addEventListener('click', function() {
	fetch('/ajax.html').then(response => {
		console.log(response.ok); // shows true or false
	});
});

Output a text of a page if the request was successful, and an error if a bad status was received.