✳ CAPTIONS · YOUTUBE SHORTS
ASS / SSA captions for YouTube Shorts
Caption QA + YouTube Shorts compatibility. Drop a ASS / SSA file to validate it against YouTube Shorts's caption rules. Stays on your device.
YouTube Shorts · does not accept ASS / SSA directly · has closed-caption support · post-text limit 100 characters
Advanced SubStation Alpha; richer styling, supported by some desktop players.
Source: https://support.google.com/youtube/answer/55744?hl=en · Verified 2026-09-12
What this checks
- Format auto-detection (SRT vs WebVTT) and parse errors
- Per-cue reading speed (warnings above 21 chars/sec)
- Negative timestamps and zero-duration cues
- Cue overlap and ordering
- YouTube Shorts post-text character limit (100)
- Closed-caption support: YES
After validating, create all platform versions in the Creator: /tools/pack
Automate this in Koldflux