Upload problems
Video upload rejected? Read the reason, then fix the file
Short answer
A rejected upload means the file or the account is outside a published limit. Work through five checks in order: container and codec, file size, duration, aspect ratio and resolution, and the account's own limits. Use ffprobe to read the file, compare it with the platform's help page, then re-export a standard MP4 with H.264 video and AAC audio.
Key takeaways
- Rejections come from format, codec, size, length, shape or account type.
- Read the file with ffprobe before changing anything.
- H.264 and AAC in MP4 is the safest default across platforms.
- Each platform's limits differ, so use its own help page, not a general table.
Published limits at a glance
From each platform's own help page, read on 2026-10-06. Limits can differ by account type, so check the composer when a file sits near the edge.
| Platform | File size | Length | Format notes |
|---|---|---|---|
| X (non-Premium) | 512 MB | Up to 140 seconds | Prompts you if the format is not supported |
| X (Premium) | Up to 16 GB | Shorter than 4 hours | 1080p; 720p for 2 to 4 hours |
| 5 GB | 15 minutes | MP4, MOV, AVI, WEBM, MKV, WMV and more; 256 × 144 to 4096 × 2304; 10 to 60 fps; 192 kbps to 30 Mbps | |
| Pinterest (organic Pins) | No video size stated | 4 seconds to 5 minutes | Web: MP4, M4V; Android and iOS: MP4, MOV, M4V; H.264 or H.265 |
| Pinterest (video ads) | 2 GB | 4 seconds to 15 minutes | MP4, MOV or M4V; H.264 or H.265 |
| YouTube | Not listed on this page | 15 minutes by default; longer once verified | MP4, AAC audio, H.264 recommended |
Find your case
| What you see | What it usually means | Do this |
|---|---|---|
| Rejected at once | Format or codec | Re-export (step 2) |
| Rejected after uploading for minutes | Size or length | Compress or trim (step 3) |
| Rejected with a policy message | Content, music or copyright | Read the message and edit the content |
| Rejected only on one account | Account limit, such as a free X account | Check the account's limits (step 4) |
Fix it step by step
Read the file
ffprobe -hide_banner in.mp4shows container, codecs, frame rate, duration and size.Export a standard file
ffmpeg -i in.mov -c:v libx264 -pix_fmt yuv420p -c:a aac -b:a 128k -movflags +faststart out.mp4.Fit size and length
Compare with the platform's limits above and compress or trim.
Check the account
Some limits depend on the account: X free vs Premium, YouTube verified vs not.
A clean export recipe
ffmpeg -i in.mov -c:v libx264 -crf 20 -preset slow -pix_fmt yuv420p -c:a aac -b:a 160k -movflags +faststart out.mp4 is a good default: widely compatible, quality-first, and ready to stream.
Check your file
Extension and MIME type are labels, not proof of the container. Dimensions and duration come from this browser's media reader. This does not detect codecs, bitrate, corruption or platform upload compatibility. Files and measurements are not sent anywhere.
Frequently asked questions
Why was my video rejected?
The file or account is outside a limit: format, codec, size, length, aspect ratio or account type.
What is the safest video format?
MP4 with H.264 video and AAC audio.
How do I see what is in my file?
Run ffprobe on it, or use a file checker, and read the codec, duration and size.
Sources
- X Help: Posting videos on X (official, checked 2026-10-06)
- Pinterest Help: Review Pin specs (organic Video Pin file types, length, aspect ratio, safe zones) (official, checked 2026-10-06)
- LinkedIn Help: Video sharing troubleshooting (formats and limits) (official, checked 2026-10-06)
- YouTube Help: Upload videos longer than 15 minutes (official, checked 2026-10-06)
Reviewed 2026-10-06. Steps not attributed to a source are general video practice or computed above.