WCAG (Level A) SC 1.2.3 Audio Description or Media Alternative (Prerecorded) (w3.org)
Issue description
WCAG 1.2.3, “Audio Description or Media Alternative (Prerecorded)” is about making sure video content isn’t just accessible to people who can see, but also to those who are blind or have low vision. It requires that for any prerecorded video with audio, you either provide an audio description or a media alternative, like a full-text transcript. Here’s why this matters:
- People who are blind can’t see the visuals: They rely on audio to understand what’s happening. Without an audio description or a transcript that describes the visuals, they miss out on key information.
- People with low vision may struggle to see details: An audio description or a comprehensive transcript can help them understand the visual elements they might miss.
Essentially, this guideline ensures that everyone can understand the information conveyed in a video, regardless of their visual abilities. It’s about providing equal access to information and creating a more inclusive online experience.
Related requirements
The following WCAG source criteria are often related to this as well. They can provide additional insights into specific challenges you may be encountering.
- WCAG (Level AA) SC 1.2.4 Captions (Live)
- WCAG (Level AA) SC 1.2.5 Audio Description (Prerecorded)
- WCAG (Level AAA) SC 1.2.6 Sign Language (Prerecorded)
- WCAG (Level AAA) SC 1.2.7 Extended Audio Description (Prerecorded)
- WCAG (Level AAA) SC 1.2.8 Media Alternative (Prerecorded)
- WCAG (Level AAA) SC 1.2.9 Audio-only (Live)
Who this issue impacts
Follow the links for additional information on user impairments:
Suggestions for remediation
To remediate WCAG 1.2.3, “Audio Description or Media Alternative (Prerecorded)” by making your video content accessible to those who are blind or have low vision, you have two main options:
Provide audio descriptions
- Describe the visuals: Create a separate audio track that describes the important visual elements in the video, including:
- Actions and events
- Characters and their appearance
- Scene changes and settings
- Body language and facial expressions
On-screen text and graphics
- Synchronization: Ensure the audio descriptions are synchronized with the video’s audio, fitting naturally within dialogue or other audio pauses.
- Clarity and conciseness: Use clear and concise language, avoiding jargon or overly descriptive language.
How to Implement
- Separate audio track: This is often preferred as it allows users to enable or disable the audio descriptions as needed.
- Integrated audio descriptions: Incorporate the descriptions into the main audio track during natural pauses. This may be simpler for basic videos but less flexible for users.
Provide a media alternative
- Full-text transcript: Create a text-based document that includes a complete transcript of the audio, along with detailed descriptions of the visual content. This allows users to access the information in a non-auditory format.
- Accessible format: Ensure the transcript is available in an accessible format, such as plain text, HTML, or a downloadable document.
Tools and resources
- YouDescribe: A free web-based tool that allows you to create and share audio descriptions for YouTube videos (YouDescribe.org).
- VoiceOver (macOS) and Narrator (Windows): Built-in screen readers that can read audio descriptions if they are present in the video file.
- Professional captioning services: Many companies offer audio description creation services.
Choosing the best option
- Complexity: For simple videos with minimal visual information, a full-text transcript might be sufficient.
- User needs: Consider your target audience and their preferences. Some users might prefer audio descriptions, while others might prefer text transcripts.
- Resources: Creating audio descriptions can be more time-consuming and expensive than creating transcripts.
Examples of options
Full-text transcript
Title: The Majestic Bald Eagle
Video Description: A majestic bald eagle soars through the sky, its white head and tail feathers gleaming in the sunlight. It circles above a pristine lake, its keen eyes scanning the water for fish.
[00:00:05]
Narrator: The bald eagle, a symbol of freedom and strength, reigns supreme in the skies of North America.
(Sound of wind rushing)
[00:00:12]
Narrator: With its piercing gaze and powerful talons, this apex predator is a master of the air.
(Music swells)
[00:00:20]
Narrator: Its wingspan can reach up to seven feet, allowing it to soar effortlessly on thermal currents.
(Video shows a close-up of the eagle’s talons)
[00:00:28]
Narrator: Those powerful talons can grasp and carry prey weighing several pounds.
(Video shows the eagle diving towards the lake)
[00:00:35]
Narrator: Watch as it dives towards the water, its speed and agility breathtaking.
(Sound of splashing water)
[00:00:42]
Narrator: It snatches a fish from the lake with incredible precision, its talons piercing the water’s surface.
(Video shows the eagle flying away with the fish in its talons)
[00:00:50]
Narrator: The bald eagle, a true marvel of nature, a symbol of the wild and untamed spirit of America.
(Music fades)
[00:01:00]
(Video ends)
—End of Transcript—
This transcript provides a text-based equivalent of the audio and visual content of the video. It includes:
- Title: A descriptive title for the video.
- Video description: A brief overview of the visual content.
- Timestamps: Timestamps indicate when different sections of the audio occur.
- Speaker identification: The narrator is identified.
- Sound descriptions: Relevant non-speech sounds are described in parentheses.
- Visual descriptions: Key visual elements are described within the narration.
This transcript allows users who cannot see or hear the video to understand its content fully. It provides a comprehensive alternative that is accessible to everyone.
Audio description
Let’s imagine a cooking video demonstrating how to make a cake. Here’s how audio description would make it accessible:
Visuals: The video shows a person measuring flour into a bowl.
Audio Description: “A person scoops flour from a bag using a measuring cup and carefully levels it off with a knife.”
Visuals: The video shows the person cracking an egg and adding it to the bowl.
Audio Description: “They crack an egg on the edge of the bowl, separating the shell, and drop the egg into the flour.”
Visuals: The video shows the person mixing the ingredients with an electric mixer.
Audio Description: “The person uses an electric mixer to combine the ingredients. The mixture starts to become smooth and creamy.”
Visuals: The video shows the batter being poured into a cake pan and placed in the oven.
Audio Description: “The batter is poured into a round cake pan and the oven door is opened. They carefully place the pan on the oven rack and close the door.”
Visuals: The finished cake is taken out of the oven, cooled, and frosted.
Audio Description: “The oven door opens, and they take out the golden brown cake. After it cools, they spread a layer of white frosting over the top, creating a smooth finish.”
This audio description allows a person who is blind or has low vision to understand the key steps and visual elements of the cake-making process. It provides context and detail that would otherwise be inaccessible to them.
