<input id="browse" type="file" onchange="previewFiles()" multiple>

<script>
    function previewFiles() {
        var files = document.querySelector('input[type=file]').files;

        function readAndPreview(file) {
            if (/\.(jpe?g|png|gif)$/i.test(file.name)) {
                console.log(file.name)
            }
        }
        if (files) {
            [].forEach.call(files, readAndPreview);
        }
    }
</script>