Burn captions into a video for X / Twitter

Soft subtitles are stored as a separate track inside the video container (MKV, MP4) and rendered by the player at playback time. They can be turned on or off, and are stripped or ignored by most social platforms. Hard subtitles (burned-in) are rendered onto the video frames themselves — they are part of the picture and cannot be turned off. Hard subs are required for social media posts, accessible offline playback, and any delivery format that doesn't support subtitle tracks.

Timestamp sync issues usually mean your SRT was created for a different cut of the video — either a different start time, or a different frame rate. Check that your SRT timestamp origin (00:00:00,000) matches the video start. If the captions are consistently early or late by a fixed offset, use the delay/offset field in JAD to shift all timestamps. Frame-rate mismatches (23.976 vs 25 fps) cause gradual drift and require re-timing the SRT.

Yes — JAD passes ASS/SSA files directly to FFmpeg's libass renderer, which supports the full ASS v4+ spec including custom fonts (embedded in the ASS file), karaoke effects, per-line positioning, shadows, border styles, and scroll animations. Upload the ASS file alongside the video and the styles are preserved in the burned output.