All audio and video uploaded to a university website or social media site must have captions. You can auto-generate captions in both YouTube and Facebook, but you must edit them to ensure complete accuracy. Guidelines require that captions be at least 99% accurate in order to be considered accessible. Even the best automated captioning services will mess up important information like names and proper nouns.
Open captions are "burned in" to the video itself - they are always present and cannot be turned off. Closed captions exist as a separate file alongside the video and can be turned on and off.
The Web Content Accessibility Guidelines (WCAG) AA 2.1 do not specify a preference for either open or closed captions. Closed captions are more flexible: they can scale to be larger on small devices like phones and can exist in multiple languages. Open captions are useful as a fallback for platforms like Instagram and TikTok that don't support closed captions.
In general, W&M Libraries prefers closed captions. Our captioning vendor provides additional useful services like changing the placement of the captions, a library of terms to avoid misspelling names, and Word doc transcripts in addition to the caption files at no additional cost. They also support YouTube and can push finalized captions out directly to YouTube so you don't need to upload the files manually.