Alt text for videos is referred to as a transcript. You should always provide a transcript of the video - which includes the text of the captions and descriptions of the visual part of the video. This visual part of any video must always have an alternative, and it can be provided via a transcript OR via audio descriptions (which are spoken descriptions for people who are blind or vision impaired) at Level A. At Level AA you are required to provide audio descriptions.
If you need assistance in developing transcripts, captions and audio descriptions we have a specific CCC price available and you can request a quote. You may also be interested in our Video Factsheet.