The 9:16 format
The dashboard's Format switch has two options: Thumbnail (16:9, the YouTube standard) and Story / Short / Reel (9:16 vertical, roughly 1080×1920). The vertical option composes the whole image for a full-screen phone — subject, headline and key visuals all fit inside the tall frame, with no letterboxing and no cropped edges.
It is not a crop of a horizontal image. Choosing 9:16 changes how the frame is composed from the start, which is why a vertical generation looks right and a cropped 16:9 usually does not.
Paid feature
The 9:16 format is unlocked on Starter and above. On Free the tile shows a lock and the switch will not move. See plans and limits.
Where a vertical image actually goes
| Surface | What the 9:16 image is used as |
|---|---|
| YouTube Shorts | Custom cover, and end-card / promo art |
| Instagram Reels | Cover frame and feed promo |
| TikTok | Cover image |
| Instagram / Facebook Stories | The story graphic itself |
| YouTube Community posts | Vertical promo image for an upcoming video |
Designing for a full-screen phone
Vertical is a genuinely different design problem from a thumbnail, and the differences are not stylistic — they are about what the platform's UI covers up.
- Keep the important third in the middle. Platform chrome — captions, handles, action buttons, progress bars — eats the top and bottom of a vertical frame. Anything that must be read belongs in the central band.
- One subject, filling more of the frame. A vertical frame is narrow. Two people side by side, which works fine at 16:9, cramps badly at 9:16.
- Stack text, do not spread it. Two short lines stacked read better than one long line squeezed edge to edge.
- Expect it at arm's length in bright sun. Contrast matters even more than on a thumbnail. Dark subject on light background, or the reverse — never mid-tone on mid-tone.
Making both from one video
If a video ships as both a long-form upload and a Short, generate them separately rather than resizing one:
- Generate the 16:9 thumbnail with your usual brief.
- Switch Format to Story / Short / Reel, keep the same avatar, mood and headline, and generate again.
- You now have two natively-composed images that share a face, a grade and a headline — recognisably the same campaign, correctly built for two different frames.
Both are separate generations and each costs one request. That is still cheaper, and much better, than paying a cropping tool in awkward composition.
Editing a vertical image
Everything in the editor works the same on a 9:16 image — moods, expressions, text layers, face swap. The stage simply renders taller. Text layers are positioned as percentages of the frame, so a layer stays where you put it regardless of aspect ratio.
If you need other sizes
For platform sizes Thumblore does not generate directly — square posts, banners, ad units — download the image and run it through our free social media image resizer, which cuts one hero image to every aspect ratio a platform expects. It runs in your browser and nothing is uploaded.