Make video and audio accessible
Videos, audio files, and any other synchronized or time-based media need alternatives to make them accessible to more people. Visual content needs to be described for people who are blind or have limited vision. Auditory content needs to be described for people who are deaf or hard of hearing.
Transcripts, captions, and audio descriptions allow more people to access your media. Considering these alternatives during the planning, scripting, and creation process will help you create more accessible media from the start. Keep the following suggestions in mind:
- Limit background noise to help people hear the speech or main audio.
- Avoid flashing and blinking light to not cause seizures.
- Present the media on an accessible player.
For in-depth information, see the Web Accessibility Initiative (WAI) resource on media alternatives and other considerations
The following will help you choose which alternatives you need for your media.
You must provide a transcript or other text alternative for audio-only media. While not required for video with audio, a descriptive transcript is strongly recommended to allow access to your media for the most people possible. Transcripts let everyone access a text version of the media, including people who are deaf or blind. HTML transcripts are also important for search engines, which can index the transcript, improving search engine optimization (SEO).
A simple transcript includes the speech and non-speech audio information. A more thorough, descriptive transcript also includes visual information. You can use the closed captions and audio description script to start producing a transcript. Transcripts can be linked from a separate page, integrated on the same page, or interactive. Although you can use PDF or other document types for transcripts, HTML is the preferred format.
Captions should be synchronized and accurate, presenting the same content available in the audio track. The captions should not cover important images, including other text in the video, and should have enough color contrast to be visible.
Captions allow people who are deaf or hard of hearing access to the audio information. People in quiet or noisy environments, non-native speakers of the language, and people listening to an unfamiliar accent also benefit from closed captions.
The audio description should be inserted in natural pauses in the narration or dialog near the time the referenced action happens. Extended audio description, requiring the video and audio tracks to be programmatically paused to insert the description, may be used when the audio description doesn't fit into natural pauses in the narration or dialog. A carefully planned video can be designed to include natural pauses where the audio descriptions can be inserted with few interruptions.
Audio descriptions help people who are blind or visually impaired. Audio descriptions should be a separate, selectable track if possible. If multiple audio tracks are not possible, then the audio description version of the video can be linked.