118: Aaron Gustafson - Semantic HTML: The Hard Parts

What It Covers

Aaron Gustafson from Microsoft Edge explains semantic HTML for web applications, covering heading hierarchies, sectioning elements like article and aside, navigation patterns, form labels, and how proper markup enables screen readers and digital assistants to parse content.

Key Questions Answered

• •Heading hierarchy: Use single h1 per page as most important element, followed by h2s and h3s in proper order. HTML5 sectioning elements never implemented automatic outline algorithm, so sequential heading levels remain critical for screen readers navigating document structure and assistive technology understanding page organization.
• •Article element definition: Think of articles as individual items that stand alone independently, like articles of clothing rather than publication articles. Each Airbnb listing card, tweet, or blog post qualifies as an article element. Pages can contain unlimited articles without confusing screen readers or creating accessibility issues.
• •Hidden heading strategy: Major sites like Facebook use visually hidden headings to create proper document outlines separate from visual design. Each section receives an h2 title even when not displayed, allowing screen readers to navigate while designers maintain visual flexibility without compromising semantic structure or accessibility requirements.
• •Form label requirement: Always use label elements with for attributes to associate text with form fields. This creates accessible names for assistive technology, expands clickable areas for checkboxes and radio buttons, automatically focuses fields when labels are clicked, and represents the easiest accessibility improvement developers can implement immediately.
• •Description lists for metadata: Use dl, dt, and dd elements for key-value pairs like price per night, location, or post metadata instead of generic divs. Description lists provide semantic structure for data relationships, remain underutilized despite broad applicability, and offer better accessibility than paragraph or span alternatives for structured information.