Video & Multimedia Accessibility: Making Your Content Accessible to Everyone

Introduction

Video represents 80% of internet traffic. If your videos aren't accessible, you're excluding millions of users and creating significant legal liability. Video accessibility isn't optional—it's essential for WCAG 2.1 compliance and user experience.

This guide covers everything you need to know about making video and multimedia content accessible: captions, audio descriptions, transcripts, keyboard controls, and more.

Captions: Making Audio Accessible

Why Captions Matter

Captions aren't just for deaf users. They benefit people watching in noisy environments, non-native speakers, and users who simply prefer reading along. Captions are required for WCAG 2.1 Level A compliance for pre-recorded video content.

Types of Captions

Open Captions are burned into the video and always visible. Closed Captions (CC) can be toggled on and off, allowing viewers to choose. Closed captions are almost always preferable because they give users control.

Caption Quality Standards

Captions must be accurate, properly synchronized with audio, and include speaker identification. They should describe relevant sounds (door slams, background music changes) using brackets: [door creaks open]. Avoid spelling errors, poor timing, or missing dialogue. Poor captions are worse than no captions.

Caption Placement & Readability

Position captions in the lower third of the video, but avoid covering important visual content. Use readable fonts (sans-serif, 18-24pt minimum), high contrast backgrounds (dark background with white text), and adequate padding around text. Test captions at multiple screen sizes.

Audio Descriptions: Explaining What People See

Who Needs Audio Descriptions

Audio descriptions (also called video descriptions or descriptive audio) provide narrated explanations of visual content for blind and low-vision users. For WCAG 2.1 Level AA compliance, pre-recorded video requires audio descriptions for important visual content.

What Should Be Described

Describe important visual elements: character actions, scene changes, text on screen, graphs, demonstrations, and facial expressions. Avoid describing obvious elements (people talking) but do describe how they look or their setting. Audio descriptions should fill gaps between dialogue without overlapping.

Creating Audio Descriptions

Write a script describing visual content in short, clear sentences. Record audio in a quiet environment with a clear voice. Edit descriptions into natural pauses in dialogue. Alternatively, provide a separate audio description track that viewers can enable. Many video platforms support this natively.

Tools for Audio Descriptions

YouTube automatically generates descriptions (not always accurate—review them). Professional services include 3Play Media, Rev, and Accessibility Solutions. For live events, trained describers provide real-time audio descriptions through a separate audio feed.

Transcripts: Full Text Records

Why Transcripts Are Essential

Transcripts are full text versions of video content. They benefit deaf users, people with processing disabilities, and users who prefer reading. Transcripts also improve SEO—search engines can't watch videos but can index transcript text. WCAG 2.1 requires transcripts for videos containing important information.

Creating Comprehensive Transcripts

Include all dialogue, speaker names, sound effects in brackets [laughter, applause], and descriptions of important visual content. Format transcripts with clear headings and sections. Make transcripts searchable and easy to navigate. Link transcripts prominently near the video player.

Searchable & Linked Transcripts

The best transcripts are linked directly below or beside the video, not hidden behind a link that says "read transcript." When possible, make transcripts searchable (Ctrl+F) so users can find specific content. Include timestamps so users can jump to relevant sections.

Transcript Tools

YouTube generates automatic transcripts (usually 80-90% accurate—always review). Rev, 3Play Media, and Descript provide professional transcription. For live content, CART (Communication Access Realtime Translation) services provide real-time transcripts.

Video Player Accessibility: Controls & Keyboard

Keyboard Accessibility Requirements

Video players must be fully operable via keyboard. Users should be able to Tab to the player, then use standard keys: Space to play/pause, arrow keys to skip forward/backward, M to mute, and F for fullscreen. All controls must have visible focus indicators.

Essential Controls

Players need: play/pause, volume control, progress bar with current time, captions toggle, audio description toggle (if available), fullscreen button, and settings menu. Each control needs a label and keyboard shortcut. Screen readers should announce control names and states.

Focus Management

When a user enters the video player, focus should move to the first control. When they exit, focus should move logically to the next page element. Ensure focus doesn't get trapped inside the player. Test with keyboard only—Tab, Shift+Tab, and arrow keys should work smoothly.

Accessible Video Player Solutions

YouTube and Vimeo have built-in accessibility features. Video.js is an open-source player with good accessibility. Kaltura, JW Player, and Brightcove offer enterprise solutions. Always test your chosen player for keyboard accessibility and screen reader compatibility before deploying.

Live Video: Real-Time Captioning & Descriptions

Live Captions for Real-Time Events

Live events require real-time captions. CART (Communication Access Realtime Translation) providers employ trained stenographers who caption live content in real-time. Accuracy is typically 98%+ but requires experienced CART operators. This is expensive but essential for legal compliance and user experience.

Live Audio Descriptions

For live events, trained describers provide audio descriptions through a separate audio feed. Viewers can enable the description track on their device. This requires coordination with event organizers and audio infrastructure.

Alternative: Post-Event Captions & Descriptions

If live captions aren't feasible, record the event and caption/describe it afterward. Within 7-14 days is a reasonable turnaround. Post the captioned/described version to your website and notify viewers that accessible versions are available.

Testing Live Accessibility

Test CART quality before the event. Ensure caption display is readable (size, positioning, background contrast). Test audio description audio level and clarity. Have backup CART operators in case primary operator has technical issues.

Audio-Only Content: Podcasts & Audio Files

Podcasts & Accessibility

Podcasts are audio-only content that requires transcripts. Include show notes, speaker names, and timestamps. For best accessibility, provide transcripts alongside the podcast player. Platforms like Anchor and Transistor can generate automatic transcripts.

Music & Sound Effects

Describe important audio elements that convey information. If your audio relies on music to convey emotion, don't—use clear language instead. If sound effects convey important information, provide visual or textual alternatives.

Audio File Best Practices

Always provide transcripts for audio content. Link transcripts directly from the audio player. Make transcripts searchable. For long-form audio, break transcripts into sections with timestamps so users can jump to relevant content.

Beyond Video: Multimedia Accessibility

Animations & Animated GIFs

Animations can convey important information but may confuse screen reader users. Provide text alternatives. Avoid animations with more than 3 flashes per second (seizure risk). Respect prefers-reduced-motion settings. If animation is purely decorative, hide it from screen readers with aria-hidden="true".

Interactive Multimedia

Interactive content (simulations, games, educational tools) must be keyboard accessible and screen reader compatible. Provide keyboard alternatives for mouse interactions. Include transcripts or text alternatives for important information. Test thoroughly with assistive technology.

Embedded Content

When embedding third-party content (YouTube videos, interactive maps), ensure the embed is accessible. Provide titles and descriptions. Make sure keyboard navigation works. If third-party content isn't accessible, provide an accessible alternative.

Video Accessibility Compliance Checklist

WCAG 2.1 Level A (Minimum)

Captions for all pre-recorded video and audio. Audio descriptions for important visual content. Transcripts for audio-only content. Video player keyboard accessible.

WCAG 2.1 Level AA (Recommended)

Accurate, well-timed captions. Audio descriptions for all important visual content. Searchable transcripts with timestamps. Full keyboard control of video player. Screen reader compatible controls.

Beyond WCAG: Best Practices

Sign language interpretation for important content. Multiple caption styles for different preferences. Audio description toggle (not forced). High-contrast captions. Clear player design. Accessible video landing pages with descriptions.

Resources & Tools

• W3C: Audio and Video Accessibility
• 3Play Media - Captioning & Transcription
• Rev - Professional Transcription
• Descript - Video Editing with Transcripts
• Video.js - Accessible Video Player
• WebAIM: Captions, Transcripts, and Audio Descriptions
• AERT - Media Accessibility

Key Takeaways

• Captions are required for WCAG compliance and benefit all users, not just deaf viewers.
• Audio descriptions make video content accessible to blind and low-vision users.
• Transcripts improve accessibility, SEO, and user experience simultaneously.
• Video player keyboard controls and screen reader compatibility are essential.
• Live events require real-time CART captions or post-event captioning.
• Podcast transcripts should be searchable with timestamps.
• Test all video accessibility with real users and assistive technology.
• Accessible video content reaches larger audiences and ranks better in search.