Animated ARIA hamburger menu

In this example below you will see how to do a Animated ARIA hamburger menu with some HTML / CSS and Javascript

WCAG 2 level AA hamburger menu with animation. Vanilla JavaScript, zero dependencies.

This awesome code was written by 2kool2, you can see more from this user in the personal repository.
You can find the original code on
Copyright 2kool2 ©
  • HTML
  • CSS
  • JavaScript
<!DOCTYPE html>
<html lang="en" >

  <meta charset="UTF-8">
  <title>Animated ARIA hamburger menu</title>
  <link rel='stylesheet prefetch' href='css/kxqoaa.css'>

      <link rel="stylesheet" href="css/style.css">



  <h1>Animated <abbr title="Accessible Rich Internet Applications">ARIA</abbr> hamburger menu to meet <abbr title="Web Content Accessibility Guidelines">WCAG</abbr> 2 level AA</h1>

<p>I needed a non-linear show-hide peekaboo to meet WCAG 2 level AA.<br> This one ticks the boxes, and a reusable asset to boot.</p>

<p>JavaScript is used to toggle ARIA states and control tab position while CSS attribute selectors control animation.<p>

  <a id="hamburger" href="#navigation" class="menu">
    <svg class="menu_svg" viewbox="0 0 48 48">
      <rect x="15.5" y="16.5" width="20" height="3"/>
      <rect x="15.5" y="23.5" width="20" height="3"/>
      <rect x="15.5" y="30.5" width="20" height="3"/>

<p>A <a href="#">Fake Site Search</a> between the Menu link and the navigation block.<br>Arrgh, the things you have to deal with&hellip;</p>

<nav id="navigation" class="navigation">
  <h2 class=navigation_title>Main navigation:</h2>
  <ul class=navigation_list>
    <li><a href="#"></a></li>
    <li><a href="#">Groceries</a></li>
    <li><a href="#">Tesco direct</a></li>
    <li><a href="#">F&amp;F clothing</a></li>
    <li><a href="#">Clubcard</a></li>
    <li><a href="#">Tesco Bank</a></li>
    <li><a href="#">Wine by the case</a></li>
    <li><a href="#">Tesco Mobile</a></li>

<p><a href="#">Fake link after navigation block</a> to test keyboard <kbd>Tab</kbd> order.</p>

<p>Strongly influenced by the work of Heydon Pickering</p>

    <script  src="js/index.js"></script>



/*Downloaded from */
/* Simple animated Peekaboo show-hide */

/* Generic styling (not required) */

.menu {
  width: 40px;
  height: 40px;
  border: 0 solid;

.menu_svg {
  pointer-events: none;

.menu[aria-expanded="true"] {
  background-color: #1A1A1A;
  fill: #fff;

/* The heavy lifting is done by  3 statements */

.navigation {
  position: relative;
  margin: 0;
  padding: 0;
  transform: translate3d(0,0,0);
  backface-visibility: hidden;

  /* opacity has to finish before height to allow JS time to find first link */
  transition: visibility 0s ease-out, opacity .3s linear, max-height .5s ease-out;
  opacity: 0;
  visibility: hidden;
  max-height: 0;
  overflow: hidden;

.navigation[aria-hidden="true"] {
  transition-delay: .6s, 0s, 0s;

.navigation[aria-hidden="false"] {
  transition-delay: 0s, 0s, 0s;
  opacity: 1;
  visibility: visible;
  max-height: 12em;

/* More generic styling */

.navigation_title {
  margin: 0;
  padding: 0;
  position: absolute;
  left: -200em;

.navigation_list {
  margin: 0;
  padding: 0 2em;

.navigation_list li {
  width: 50%;
  float: left;

/*Downloaded from */
function peekaboo(w, d, linkBtnId) {

  // Peekaboo - show-hide toggle
  // Toggle a section using ARIA

  "use strict";
  var openLabel = "Open and skip to navigation bypassing site search";
  var closeLabel = "Close and hide navigation";

  var _getRegionObj = function (linkObj) {
    return d.getElementById(linkObj.hash.replace("#", "")) || !1;

  var _setAriaStates = function (linkObj, regionObj, isExpanded) {
    w.requestAnimationFrame(function () {
      linkObj.setAttribute("aria-expanded", isExpanded);
      regionObj.setAttribute("aria-hidden", !isExpanded);
      linkObj.setAttribute("aria-label", isExpanded ? closeLabel : openLabel);

  var _toggleAriaStates = function (e) {

    var linkObj =;
    var expanded = linkObj.getAttribute("aria-expanded") || !1;

    if (expanded) { // string "false" is boolean true here
      var regionObj = _getRegionObj(linkObj);
      if (regionObj) {

        // convert to boolean
        expanded = expanded === "true"; 
        _setAriaStates(linkObj, regionObj, !expanded);
        if (expanded) {
        } else {

          // Small delay required for focusable object to reappear in DOM
          // (transitionend event would have CSS dependencies)
          setTimeout(function() {
            (regionObj.querySelector("a") || regionObj).focus();
          }, 100);

  var _addAriaAttributes = function (linkObj) {

    var regionObj = _getRegionObj(linkObj);
    if (regionObj) {
      _setAriaStates(linkObj, regionObj, false);
    return regionObj;

  var initialise = function () {

    var anchor = d.getElementById(linkBtnId);
    if (anchor && _addAriaAttributes(anchor)) {
        anchor.addEventListener("click", _toggleAriaStates, !1);

  return initialise();


peekaboo(window, document, "hamburger");