index.html

<meta charset="utf-8"/>

<style>
body {
    padding-top: 10vh;
    text-align: center;
}

a {
    display: block;
    padding: 10px 0;
}

input {
    width: 50px;
}

</style>

<title>Random maze generators</title>
<h1>Random maze generators</h1>

<label>
    Cell size (in pixels):
    <input type="text" value="50" id="cell-size">
</label>

<a href="#" id="link-backtracker">Recursive backtracker</a>
<a href="#" id="link-prim">Prim</a>

<script>
    const get = id => document.getElementById(id)
    const cellSize = () => get('cell-size').value

    get('link-backtracker').addEventListener('click', () => {
        location.href = 'recursive-backtracker.html?cell-size=' + cellSize()
    })

    get('link-prim').addEventListener('click', () => {
        location.href = 'prim.html?cell-size=' + cellSize()
    })
</script>