Accessibility standards do not require subtitles. Subtitles are text translations of other languages. Captions are required at the most basic level, WCAG Level

Accessibility standards do not require subtitles. Subtitles are text translations of other languages. Captions are required at the most basic level, WCAG Level A, for recorded media. At Level AA, they're required for live video. Captions are for the hearing impaired. There are also requirements for audio description for the vision impaired (additional audio describing important aspects of a video not conveyed through the original audio track). There's very little enforcement of this as it's often challenging to produce and non-synced text is often good enough. https://www.w3.org/WAI/WCAG20/quickref/#media-equiv https://www.w3.org/WAI/WCAG20/quickref/#media-equiv