TikTok, Reels and Shorts video size and aspect ratio
For TikTok, Instagram Reels and YouTube Shorts, the standard is vertical 9:16 video at 1080 by 1920 pixels. Choosing the right format before you generate matters more than fixing it afterward, because cropping a wide video into a tall frame throws away most of the picture.
Quick reference
Platform requirements change. Always check each platform's current creative specifications before running paid campaigns.
- TikTok, Instagram Reels, YouTube Shorts: 9:16, 1080 by 1920.
- Instagram and Facebook feed: 1:1 or 4:5 also work well.
- YouTube standard videos, website hero sections: 16:9, 1920 by 1080.
Generate in the final ratio
If you generate a 16:9 clip and crop it to 9:16, you keep only a narrow strip of the frame. Anything that sat near the sides, such as a product label, can disappear. Pick the ratio you will publish in before generating.
Leave room for the app interface
Each app overlays buttons, captions and profile information on top of the video. Keep the main subject near the center and avoid putting important details close to the top or bottom edges.
In your prompt you can ask for this directly, for example: keep the subject centered and leave empty space at the top for a caption.
How long should the clip be?
There is no single correct length. Short clips of about 5 to 8 seconds are a practical starting point for AI generation because they are cheaper to test and drift less. You can combine several in an editor for longer videos.
Whatever the length, make the first two seconds visually interesting. That is a common guideline for short-form video, not a platform rule.
Checklist before you post
- Is it 9:16 and at least 1080 by 1920?
- Is the main subject in the center?
- Have you added captions and sound where useful?
- Does the platform require you to label AI-generated content? Check the current rules.