✳ CAPTIONS · SUBSTACK
Embedded soft subtitles captions for Substack
Caption QA + Substack compatibility. Drop a Embedded soft subtitles file to validate it against Substack's caption rules. Stays on your device.
Substack · may accept Embedded soft subtitles (verify with the platform)
A subtitle stream inside the video container (e.g. MKV with multiple tracks).
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
After validating, create all platform versions in the Creator: /tools/pack
Automate this in Koldflux