Code Errors – HTML
HTML used to implement content on webpages follow a set of semantic rules.
These rules MUST be followed to reliably present the content correctly.
NOTE:
- New to accessibility or uncertain of requirements, it will be helpful to review all sections below.
- Already familiar with requirements, skip to the “Working Example” section for sample HTML, CSS and JavaScript (when needed), along with a working demo.
To avoid validation errors in HTML pages, make sure that the following statements are true:
-
Ensure that HTML tags SHOULD contain start (
< >) and end (</>) tags. Some tags like<img>,<hr>and so on are exceptions as they do not contain an end tag. - HTML elements SHOULD be nested properly wherever nesting is used.
- HTML elements SHOULD NOT contain duplicate attributes.
- HTML elements SHOULD have unique IDs.
-
Where possible, native HTML elements (
<button>,<input type="button">, etc.) SHOULD be used rather than an ARIA role (role="button"). - Use appropriate HTML elements for the correct activity, e.g. links SHOULD be used for navigation and buttons SHOULD be used for actions.
- Test your code with an HTML validator such as the W3C’s validator or HTML NU Checker to ensure that no semantic errors exist on in your code.
Note: As per latest WCAG update, the parsing requirement is deprecated due to the handling of code by modern browsers where many of the semantics are taken care of. Whereas other requirements are taken care of by other success criteria requirements. For more information, visit https://www.w3.org/WAI/WCAG21/Understanding/parsing.html .
A well-defined HTML page without code errors benefits majorly the below users.
- People with cognitive disabilities
- People with visual disabilities
- People using speech input
- People with limited dexterity
<header id="nav-menu" aria-label="navigation bar">
<div class="nav-container">
<div class="nav-start">
<a class="logo" href="/">
<span>Pearson</span>
</a>
<nav class="menu">
<ul class="menu-bar">
<li><a class="nav-link" href="#">Home</a></li>
<li><a class="nav-link" href="#">About</a></li>
<li><a class="nav-link" href="#">Service</a></li>
<li><a class="nav-link" href="#">Contact</a></li>
<li><a class="nav-link" href="#">Careers</a></li>
</ul>
</nav>
</div>
<div class="nav-end">
<button id="hamburger" aria-label="hamburger" aria-haspopup="true" aria-expanded="false">
<i class="bx bx-menu" aria-hidden="true"></i>
</button>
</div>
</div>
</header>
<main>
<h1>Code Error - HTML</h1>
<div class="container">
<section class="cards">
<article class="card reorder">
<h2><a href="#" id="cardtitle2">StatCrunch</a></h2>
<img src="https://www.pearson.com/content/dam/global-store/global/educator/1600x800-offset-758832-LowRe.jpg.transform/card-size/img.jpeg" alt="StatCrunch Image" loading="lazy" width="500" height="200">
<p>Put the power of data in students’ hands as they analyze data sets easily from their text and exercises</p>
<a href="#" aria-describedby="cardtitle2">Explore StatCrunch</a>
</article>
<article class="card reorder">
<h2><a href="#" id="cardtitle1">Learning Catalytics</a></h2>
<img src="https://www.pearson.com/content/dam/global-store/global/educator/1600x800-GettyImages-1138142697-LowRe.jpg.transform/card-size/img.jpeg" alt="Learning Catalytics Image" loading="lazy" width="500" height="200">
<p>Hear from every student when it matters most as they respond using their own smartphones, tablets or laptops</p>
<a href="#">Explore Learning Catalytics</a>
</article>
<article class="card reorder">
<h2><a href="#" id="cardtitle3">MediaShare</a></h2>
<img src="https://www.pearson.com/content/dam/global-store/global/educator/1600x800-iStock-1135957607-LowRe.jpg.transform/card-size/img.jpeg" alt="MediaShare Image" loading="lazy" width="500" height="200">
<p>Bring course concepts to life and engage students with media-rich activities, created with Pearson or your own content</p>
<a href="#" aria-describedby="cardtitle3">Explore MediaShare</a>
</article>
</section>
<aside>
<div class="fld-press-release-report-item">
<div class="press-release-content-box">
<div class="section-heading-content-title"><h2>Latest Annual Report</h2></div>
<div class="section-heading-link-download">
<a href="#" class="button-secondary filelink">Annual Report 2022</a>
</div>
</div>
<div class="press-release-image-box">
<div class="press-release-content-image">
<img src="https://plc.pearson.com/sites/pearson-corp/files/pearson/investors/ir-landing-media.png" alt="">
</div>
</div>
</div>
</aside>
</div>
</main>
<footer>
<ul class="footer-link">
<li><a href="#">Terms of Use</a></li>
<li><a href="#">Privacy Statement</a></li>
<li><a href="#">Patent Notice</a></li>
<li><a href="#">Accessibility Statement</a></li>
<li><a href="#">Accessibility Conformance Reports</a></li>
<li><a href="#">Contact Us</a></li>
</ul>
<p>© Copyright © 1996–2023 Pearson All rights reserved.</p>
</footer>
* {
margin: 0;
padding: 0;
box-sizing: border-box;
font-family: "Inter", sans-serif;
}
:root {
--light-grey: #eeeeee;
--border: 1px solid var(--light-grey);
}
body {
font-family: Arial, sans-serif;
margin: 0;
padding: 0;
}
ul { list-style: none; }
a {
text-decoration: none;
color: inherit;
}
button {
border: none;
background-color: transparent;
cursor: pointer;
color: inherit;
}
.icon {
padding: 0.5rem;
background-color: var(--light-grey);
border-radius: 10px;
}
.logo { margin-right: 1.5rem; }
#nav-menu { border-bottom: var(--border); }
.nav-container {
display: flex;
align-items: center;
justify-content: space-between;
column-gap: 2rem;
height: 90px;
padding: 1.2rem 3rem;
background-color: #005a70;
}
.menu {
position: relative;
background: #005a70;
color: #fff;
}
.menu-bar li:first-child .dropdown {
flex-direction: initial;
min-width: 480px;
}
.menu-bar li:first-child ul:nth-child(1) { border-right: var(--border); }
.menu-bar li:nth-child(n + 2) ul:nth-child(1) { border-bottom: var(--border); }
.menu-bar .dropdown-link-title { font-weight: 600; }
.menu-bar .nav-link {
font-size: 1rem;
font-weight: 500;
letter-spacing: -0.6px;
padding: 0.3rem;
min-width: 60px;
margin: 0 0.6rem;
}
.menu-bar .nav-link:hover,
.dropdown-link:hover {
text-decoration: underline;
}
.nav-start,
.nav-end,
.menu-bar,
.right-container,
.right-container .search {
display: flex;
align-items: center;
z-index: 1000;
}
#hamburger {
display: none;
padding: 0.1rem;
margin-left: 1rem;
font-size: 1.9rem;
}
@media (max-width: 1100px) {
#hamburger {
display: block;
color: #fff;
}
.nav-container { padding: 1.2rem; }
.menu {
display: none;
position: absolute;
top: 87px;
left: 0;
min-height: 100vh;
width: 100vw;
}
.menu-bar li:first-child ul:nth-child(1) {
border-right: none;
border-bottom: var(--border);
}
.dropdown {
display: none;
min-width: 100%;
border: none !important;
border-radius: 5px;
position: static;
top: 0;
left: 0;
visibility: visible;
opacity: 1;
transform: none;
box-shadow: none;
}
.menu.show,
.dropdown.active {
display: block;
}
.dropdown ul { padding-left: 0.3rem; }
.menu-bar {
display: flex;
flex-direction: column;
align-items: stretch;
row-gap: 1rem;
padding: 1rem;
}
.menu-bar .nav-link {
display: flex;
justify-content: space-between;
width: 100%;
font-weight: 600;
font-size: 1.2rem;
margin: 0;
}
.menu-bar li:first-child .dropdown { min-width: 100%; }
.menu-bar > li:not(:last-child) {
padding-bottom: 0.5rem;
border-bottom: var(--border);
}
}
.cards {
flex: 0 1 60%;
margin-right: 20px;
}
.cards h2 {
font-size: 24px;
margin-bottom: 10px;
color:rgb(0, 102, 204);
}
.cards p {
font-size: 16px;
line-height: 1.5;
}
main {
margin: 20px;
padding: 20px;
}
section {
display: flex;
flex-direction: row;
justify-content: center;
flex-wrap: wrap;
list-style: none;
margin: 0;
padding: 0;
}
.cards > * { flex: 0 1 20em; }
.card {
margin: .75em;
padding: .75em;
border-radius: 3px;
border: 2px #ccc solid;
border-radius: .6em;
background-color: white;
position: relative;
}
img {
width: 100%;
height: auto;
}
.reorder {
display: flex;
flex-direction: column;
}
.reorder img {
max-width: 100%;
order: -1;
}
.cards > * a {
display: block;
color: rgb(0, 102, 204);
}
.cards h2 > a { text-decoration: none; }
footer {
position: relative;
bottom: 0;
width: 100%;
text-align: center;
padding: 20px 0;
margin: 0;
background-color: #007fa3;
color: #fff;
}
footer ul li {
list-style: none;
display: inline-block;
padding: 0;
margin: 10px;
}
footer ul li a {
font-size: 18px;
color: #fff;
}
.footer ul li a:hover { text-decoration: underline; }
aside {
background-color: #f2f2f2;
padding: 20px;
margin: 20px;
flex: 0 1 30%;
height: fit-content;
}
.container {
display: flex;
flex-wrap: wrap;
justify-content: center;
}
@media (max-width: 768px) {
.cards { flex: 0 1 90%; }
}
.fld-press-release-report-item {
padding-top: 43px;
padding-left: 48px;
padding-bottom: 23px;
float: left;
}
.press-release-content-box {
display: block;
float: left;
max-width: 100%;;
}
.section-heading-content-title h2 {
font-size: 24px;
font-weight: 700;
font-stretch: normal;
font-style: normal;
line-height: 1.42;
letter-spacing: 0.5px;
color: #000;
margin-right: 35px;
}
.section-heading-link-download {
padding-top: 20px;
padding-bottom: 20px;
border-top: 4px solid #ae367e;
z-index: 10;
}
.section-heading-link-download a {
position: relative;
display: inline-block;
font-size: 16px;
font-weight: 700;
font-stretch: normal;
font-style: normal;
line-height: 1.5;
letter-spacing: 1px;
color: #000;
width: 100%;
}
.press-release-image-box {
display: block;
float: left;
}
.press-release-content-image {
position: relative;
height: 275px;
width: 212px;
}
.press-release-content-image img {
position: relative;
z-index: 1;
width: 100%;
height: 100%;
}
.press-release-content-image:after {
position: absolute;
content: "";
width: 212px;
height: 275px;
background: #fff;
border-radius: 2px;
z-index: 0;
left: 22px;
margin-top: 22px;
}
span {
font-size: 24px;
color: #fff;
}
const hamburgerBtn = document.getElementById("hamburger");
const navMenu = document.querySelector(".menu");
function toggleHamburger() {
navMenu.classList.toggle("show");
hamburgerBtn.setAttribute(
"aria-expanded",
hamburgerBtn.getAttribute("aria-expanded") === "false" ? "true" : "false"
);
}
hamburgerBtn.addEventListener("click", toggleHamburger);
Due to the nature of this demonstration, it is best
viewed full screen
.