All video content requires a text based alternative such as a transcript or captions to make it accessible by users with a vision or hearing impairment.
Captions are also useful for:
Captions should be written with the assumption the viewer cannot hear anything at all. Include:
Subtitles assume a viewer can hear but not understand the dialogue. They are used to provide translations from other languages. Subtitles may be used on part or all of a video file and can be open or closed.
Open Captions are text included as a permanent part of the video file and cannot be turned off.
Closed Captions are a separate text file listing the video dialogue and time stamps for synchronisation with the video file. A video file may have multiple linked closed caption files for a viewer to select from.
Depending on the length and quality of your video captioning can be done using a free tool such as YouTube or a Amara, or a specific application. There are also many caption service vendors available - costs and processing times vary a great deal.
Any content you use, even if it is published by someone else must be accessible. You may need to: