Media Requirements
Video and custom thumbnail requirements for YouTube, and the rules for media URLs.
Files above these limits are rejected:
- 256 GB per video
- 15 minutes on an unverified channel
- 2 MB per thumbnail after compression
Large videos (1 GB or more) can take 30 to 60 minutes or longer to process on YouTube's side.
Videos
| Property | Shorts | Video |
|---|---|---|
| Max duration | 3 minutes | 12 hours (verified), 15 minutes (unverified) |
| Min duration | 1 second | 1 second |
| Max file size | 256 GB | 256 GB |
| Formats | MP4, MOV, AVI, WMV, FLV, 3GP, WebM | MP4, MOV, AVI, WMV, FLV, 3GP, WebM |
| Aspect ratio | 9:16 (vertical) | 16:9 (horizontal) |
| Resolution | 1080 x 1920 px | 1920 x 1080 px (1080p) |
Recommended encoding:
| Property | Shorts | Video |
|---|---|---|
| Resolution | 1080 x 1920 px | 3840 x 2160 px (4K) |
| Frame rate | 30 fps | 24 to 60 fps |
| Codec | H.264 | H.264 or H.265 |
| Audio | AAC, 128 kbps | AAC, 384 kbps |
| Bitrate | 10 Mbps | 35 to 68 Mbps (4K) |
Custom thumbnails
Custom thumbnails work on videos only, not Shorts. Set thumbnail on the video media item.
| Property | Requirement |
|---|---|
| Format | JPEG, PNG, GIF |
| Max size | 2 MB |
| Recommended resolution | 1280 x 720 px (16:9) |
| Min width | 640 px |
Zernio enforces YouTube's rules before upload: JPEG, PNG or GIF, and 2 MB at most. Oversized images are compressed first, and rejected if they are still over 2 MB.
YouTube itself only accepts custom thumbnails on phone-verified channels (youtube.com/verify).
Unverified channel. The video still uploads and publishes; only the thumbnail is skipped.
Zernio remembers the refusal for 7 days and does not retry thumbnails on that channel until then. After verifying, allow up to a week for thumbnails to resume.
Media URLs
The URL must return the video bytes, not an HTML page, with no authentication and no expired link.
Or upload through the media endpoint.