Question

is there any way to empty localStorage (defined in html5) through php?

I need something like this:

<script type="text/javascript">
    window.localStorage.clear();
</script>

<?php header('Location: '.$adress); ?>

But unfortunately its not possible to call javascript before headers 🙁

Any idea how to solve this?

Answer 1

No: you will need to do the redirection in Javascript as well:

<script type="text/javascript">
    window.localStorage.clear();
    window.location = "<?= $adress ?>";
</script>

You can only manipulate localstorage with Javascript, and if you send the Location header with PHP the Javascript will not be executed.