The good news for anyone making short-form video in 2026: TikTok, YouTube Shorts, and Instagram Reels all use the same shape — vertical 9:16 at 1080×1920. So a clip built for one fits all three. The only real differences are the length limits. Here are the current specs, plus how to generate clips in the right format from the start.
TL;DR
- All three are 9:16, 1080×1920 (vertical). Build once, post everywhere.
- Max length: TikTok up to 60 min (upload), YouTube Shorts 15s–3 min, Instagram Reels up to ~20 min — but short-form still performs best well under a minute.
- Aspect ratio is the thing to get right first — generating or shooting in 9:16 avoids ugly cropping later.
- Seedance 2 supports 9:16 (and 16:9, 1:1, 4:3, 3:4), so you can pick the shape before you generate.
The specs at a glance
| Platform | Aspect / Resolution | Max length | Format |
|---|---|---|---|
| TikTok | 9:16 · 1080×1920 | up to 60 min (upload); 10 min in-app | MP4 / MOV |
| YouTube Shorts | 9:16 · 1080×1920 | 15 seconds – 3 minutes | MP4 / MOV |
| Instagram Reels | 9:16 · 1080×1920 | up to ~20 min* | MP4 / MOV |
*Reels longer than about 3 minutes aren't shown to new (non-follower) audiences, so for reach, keep them short.
Specs current as of June 2026 — platforms adjust limits periodically; double-check before a big upload.
What "9:16" actually means
Aspect ratio is the shape of the frame: width to height. 9:16 is vertical — taller than it is wide — which is why it fills a phone screen held upright. At 1080×1920 pixels, that's full-HD vertical, the native format for all three short-form platforms.
The common ratios you'll meet:
- 9:16 — vertical. TikTok, Shorts, Reels.
- 16:9 — horizontal/widescreen. Standard YouTube, most TVs.
- 1:1 — square. Older feed posts.
- 4:3 / 3:4 — older or specialized formats.
Get the ratio right at creation time. Filming or generating in 16:9 and then cropping to 9:16 throws away half your frame and often cuts off the subject.
How long should your clip actually be?
The platform maximums above are not the ideal. Short-form rewards short: most high-performing TikToks, Shorts, and Reels land between 15 and 45 seconds. Long enough to make one point, short enough to rewatch. Use the longer limits only when the content genuinely needs it.
Generate clips in the right shape
If you're making AI video for short-form, choose the aspect ratio before you generate so the output is already 9:16 — no cropping, no wasted frame. On seedance-21.app:
- Open the generator and choose Seedance 2.
- Set the aspect ratio to 9:16 (it also supports 16:9, 1:1, 4:3, 3:4).
- Write your prompt (or upload a photo for image-to-video), pick the length, and check the credit cost — it's shown before you run.
- Generate, then post the same clip to TikTok, Shorts, and Reels.
A 5-second 720p clip is ~300 credits (text-to-video) or ~150 (image-to-video); new accounts start with free credits. For multi-shot videos, generate several short 9:16 clips and stitch them in your editor. Make a vertical clip →
FAQ
What aspect ratio is TikTok / Shorts / Reels?
All three use vertical 9:16 at 1080×1920 pixels.
Can I post the same video to all three?
Yes — they share the same 9:16, 1080×1920 format, so one clip fits all of them (mind each platform's length limit).
How long can a TikTok be in 2026?
Up to 10 minutes recorded in-app and up to 60 minutes for uploads — but short clips (under a minute) perform best.
What's the ideal short-form length?
Most high-performing short-form lands between 15 and 45 seconds.
How do I make a 9:16 video with AI?
Set the aspect ratio to 9:16 in the generator before you create, so the output is natively vertical. Seedance 2 supports 9:16 and other ratios.
Resources
Making content for TikTok, Shorts, or Reels? Open the generator, set 9:16, and create a clip on your free credits.
Last updated: June 2026. Platform limits change — verify current specs before publishing.
