Accessibile Alternatives for Audio and Video

Types of Alternate Media

Alternative Media	File Formats	Details	Use
Descriptive Transcripts. Text version of the audio track and descriptions of essential visual content.	Web page / HTML is the most accessible option. Accessible text file, Word document, or PDF.	Includes dialog, names of speakers, and essential sounds. Can be displayed on the same page as the video or as a link to a webpage or document.	Pre-recorded audio or video.
Open Captions. Text overlay in the video.	The text is permanently embedded in the video.	Includes dialog, names of speakers, and essential sounds. Can’t be turned on or off. Can’t be edited.	Pre-recorded video.
Closed Captions. Text overlay in the video or displayed in a separate window.	SRT or WebVTT files. Must use a video player that supports captioning files.	Includes dialog, names of speakers, and essential sounds. Can be turned on or off in the player. Can be edited.	Pre-recorded audio or video.
Live Captions. Text overlay in the video or displayed in a separate window.	CART. Must use a video player that supports live captioning.	Includes dialog, names of speakers, and essential sounds. A captioner transcribes captions in real time.	Live audio or video stream.
Audio Descriptions (Open). Voiceover that briefly describes visual content.	The description voiceover is included in the main audio track.	Includes descriptions of essential visuals. The video length is not modified to accommodate audio descriptions. Can be turned on or off in the player. Can be edited.	Pre-recorded video.
Audio Descriptions (Closed). Voiceover that briefly describes visual content.	WebVTT file or a second audio track.	Must use a video player that supports WebVTT or additional audio tracks. Some players support turning audio descriptions on or off. Video length is not modified to accommodate audio descriptions.	Pre-recorded video.
Extended Audio Descriptions. Voiceover with detailed descriptions of all visual content.	Voiceover included in the main audio track of a video.	Extended audio is often produced as a second video with pauses when the description plays.	Pre-recorded video.

Accessible Alternatives for Video

Media	Accessible Alternative	WCAG 2.x, Level AA Compliance
Pre-recorded Video with no Audio.	Descriptive transcript and audio descriptions.	Audio descriptions.
Pre-recorded Video with Audio.	Captions and descriptive transcript. Include audio descriptions or extended audio descriptions if needed.	Captions. Audio Descriptions if needed.
Live Video.	CART captions. Include audio descriptions if needed.	Captions.

Accessible Alternatives for Audio

Media	Accessible Alternatives	WCAG 2.x, Level AA
Audio Only Pre-recorded.	Descriptive transcript	Descriptive transcript.
Audio Only Live.	CART captioning	No level AA requirement.