Workflow
Long YouTube video → Vertical short
Short answer
Take a long YouTube video to a vertical short. A workflow decides the cut, the safe-zone, the captions, and the export preset - not just the format.
The decision that matters: The right transformation depends on which words / frames survive at the target format. Validate before deciding.
Step by step
Check the source file
Use the File Doctor to confirm container, codec, duration, resolution, and file size before deciding anything.
Reframe to the target vertical aspect
Centre-cover-crop (lose sides) or letterbox (keep everything, add bars). Pick by what survives at the target resolution.
Apply the platform safe-zone
Subject + CTA inside the safe band; text/face outside the overlay.
Export with the TikTok preset
Per-platform bitrate, codec, and safe-zone. The platform constraint registry is the source of truth.
What you end up with
- Vertical short (9:16)
- Text summary / hook copy
Limits to know
- Workflow outputs depend on the source - a 60-minute podcast produces ~10 vertical clips, not 60.
- Per-platform captions and safe-zones are platform-specific, not generic.
Run the whole workflow in one place
Koldflux takes one source through checking, reframing, captions and export, and gives you a pack per platform.
Reviewed October 5, 2026 by the Koldflux team against the platform limits used by the linked tools.