$('selector').maxlength();

$('input.threshold').maxlength({
    threshold: 20,
});

$('input.few-options').maxlength({
    warningClass: "badge badge-success",
    limitReachedClass: "badge badge-warning"
});

$('input.alloptions').maxlength({
    separator: ' of ',
    preText: 'You have ',
    postText: ' chars remaining.'
});

$('textarea.textarea').maxlength({
    alwaysShow: true,
});