Free tool
YouTube Shorts size, length and format (2026)
YouTube's official limits for YouTube Shorts, checked 2026-10-21, plus a free checker for your file.
Last checked against each network's documentation on .
Limits
What YouTube accepts
Every rule below is quoted from the network's own developer or help page, linked beside it. Where a network's API reference and its help centre disagree, the API reference wins, because that is what a scheduler publishes through.
| Rule | Source |
|---|---|
| Any video MIME type. | YouTube Data API: videos.insert, checked 2026-10-21 |
| Up to 3 minutes; a longer video is uploaded as a regular video, not a Short. | YouTube Help: Upload YouTube Shorts, checked 2026-10-21 |
| Square or vertical; a landscape video is not a Short. | YouTube Help: Upload YouTube Shorts, checked 2026-10-21 |
| Shorts are uploaded at up to 1080p.(warning, not a refusal) | YouTube Help: Get started with YouTube Shorts, checked 2026-10-21 |
| At most 256 GB. | YouTube Data API: videos.insert, checked 2026-10-21 |
Character and attachment limits for YouTube are on the YouTube page.
Questions
Media limits, answered
How long can a YouTube Short be?
At most 3 min. YouTube states: "Up to 3 minutes; a longer video is uploaded as a regular video, not a Short." Source: YouTube Help: Upload YouTube Shorts, checked 2026-10-21.
What is the maximum file size for a YouTube Short?
At most 256 GB. YouTube states: "At most 256 GB." Source: YouTube Data API: videos.insert, checked 2026-10-21.
What file types does YouTube accept for a YouTube Short?
any video file. YouTube states: "Any video MIME type." Source: YouTube Data API: videos.insert, checked 2026-10-21.
Requirements by network
Run it from code
The same check is a free API: send the file's metadata, never the file. No key, JSON by default, Markdown with Accept: text/markdown.
curl -s "https://usepostify.com/api/tools/validate-media?type=video/mp4&bytes=48000000&width=1080&height=1920&duration=42"
Then schedule it in Postify
Once the file fits, Postify publishes it to every network from one composer, each with its own caption. There is a free plan with no credit card required.