Registers an unload listener

"Registers an unload listener" means that your webpage is using an unload listener, which can delay navigation and negatively impact the user experience.

How to fix it

The solution is to avoid using unload listeners. Here's how:

Step 1: Identify Unload Listeners

First, you need to identify where your code is using unload listeners. You can use Chrome DevTools for this. Open DevTools, go to the 'Sources' tab, and look through your JavaScript for unload event listeners.

Step 2: Avoid Unload Listeners

Once you've identified the unload listeners, you need to avoid them. This might involve using the beforeunload event instead, saving state periodically instead of when the page is unloaded, or redesigning your code to not rely on the unload event.

// Before
window.addEventListener('unload', function() {
  // state...

// After
window.addEventListener('beforeunload', function() {
  // state...

In this example, we've replaced an unload listener with a beforeunload listener.

Step 3: Test Your Changes

For an even better solution, consider testing your changes to make sure they don't break any functionality. This can help ensure that your site still works as expected without any unload listeners.

No time for this?

Take care of your business, we fix the PageSpeed