(more than 8 characters will likely crash the page)<br>
<input type="input" id="input">
<input type="button" value="permute" onclick="printPerms()">
<div id="output"></div>

<script>
    function allPermutations (items) {
        let results = [];
        function permute (arr, memo) {
            var cur, memo = memo || [];
            for (let i = 0; i < arr.length; i++) {
                cur = arr.splice(i, 1);
                if (arr.length === 0) {
                results.push(memo.concat(cur));
            }
                permute(arr.slice(), memo.concat(cur));
                arr.splice(i, 0, cur[0]);
            }
                return results;
        }
        permute(items);
        return results;
    }
    function printPerms() {
        var output = document.getElementById('output'),
            input = document.getElementById('input').value,
            chars = input.split('');
        
        var permutated = allPermutations(chars),
            arrangements = [];
        
        for (i in permutated) {
            arrangement = permutated[i].join('');
            if (arrangements.indexOf(arrangement) == -1) arrangements.push(arrangement);
        }

        output.innerHTML = arrangements.join('<br>');
    }
</script>