✳ CAPTIONS · TUMBLR
WebVTT captions for Tumblr
Caption QA + Tumblr compatibility. Drop a WebVTT file to validate it against Tumblr's caption rules. Stays on your device.
Tumblr · may accept WebVTT (verify with the platform)
Sidecar .vtt file with timestamps; required by HTML5 <track>.
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