The subtitles appear only on new videos, and there’s currently no way to preview or edit them.
Twitter this week began rolling out automatic captions for videos. The mobile and web-based feature marks a step forward for accessibility on the social network. There’s a catch, though: Auto-captions appear only on new videos; non-subtitled content shared before Tuesday will not receive retroactive captioning. For Android and iOS users, text appears automatically during a muted clip. You can, however, set captions to remain on even after increasing your device’s volume. On the web, use the “CC” button to toggle them on or off.
