Cover frame — Upload & scheduling — VidVertex Docs

Cover frame

A cover moment picked in the editor's render preview rides with the upload, and what happens to it depends on the mode. No pick means the platform chooses its own frame, exactly as before.

Upload mode What happens to your cover pick
Zernio API sent as a thumbnail time — Instagram and TikTok take one
Zernio CSV a JPG is cut from each variant and its URL ships with the row
Metricool API not sent: the API has no documented field for a cover, and the run log says so
Metricool (Drive + CSV) a JPG is cut from each variant and its URL ships with the row
NOTE

YouTube is deliberately not in that list. Shorts take no custom thumbnail, so no cover is sent there in any mode.