In modern browsers, there are two types of notifications:
- Desktop notifications - simple to trigger, work as long as the page is open, and may disappear automatically after a few seconds
- Service Worker notifications - a bit more complicated, but they can work in the background (even after the page is closed), are persistent, and support action buttons
The API call takes the same parameters (except for actions - not available on desktop notifications), which are well-documented on MDN and for service workers, on Google's Web Fundamentals site.
Below is a working example of desktop notifications for Chrome, Firefox, Opera and Safari. Note that for security reasons, starting with Chrome 62, permission for the Notification API may no longer be requested from a cross-origin iframe, so we can't demo this using StackOverflow's code snippets. You'll need to save this example in an HTML file on your site/application, and make sure to use localhost:// or HTTPS.
// request permission on page load
document.addEventListener('DOMContentLoaded', function() {
if (!Notification) {
alert('Desktop notifications not available in your browser. Try Chromium.');
return;
}
if (Notification.permission !== 'granted')
Notification.requestPermission();
});
function notifyMe() {
if (Notification.permission !== 'granted')
Notification.requestPermission();
else {
var notification = new Notification('Notification title', {
icon: 'http://cdn.sstatic.net/stackexchange/img/logos/so/so-icon.png',
body: 'Hey there! You\'ve been notified!',
});
notification.onclick = function() {
window.open('http://stackoverflow.com/a/13328397/1269037');
};
}
}
<button onclick="notifyMe()">Notify me!</button>
We're using the W3C Notifications API. Do not confuse this with the Chrome extensions notifications API, which is different. Chrome extension notifications obviously only work in Chrome extensions, and don't require any special permission from the user.
W3C notifications work in many browsers (see support on caniuse), and require user permission. As a best practice, don't ask for this permission right off the bat. Explain to the user first why they would want notifications and see other push notifications patterns.
Note that Chrome doesn't honor the notification icon on Linux, due to this bug.
Final words
Notification support has been in continuous flux, with various APIs being deprecated over the last years. If you're curious, check the previous edits of this answer to see what used to work in Chrome, and to learn the story of rich HTML notifications.
Now the latest standard is at https://notifications.spec.whatwg.org/.
As to why there are two different calls to the same effect, depending on whether you're in a service worker or not - see this ticket I filed while I worked at Google.
See also notify.js for a helper library.
