Cannot upload a video to X: prepare a smaller MP4
If a video upload fails on X, check the format and upload route as well as its size. The applicable conditions can depend on the feature and account you are using.
Open tool →Destination file-size and duration requirements
| Sending or publishing method | Size requirement | Duration and other conditions |
|---|---|---|
| Standard post without Premium | Up to 512MB | Up to 140 seconds |
| Long-form uploads with X Premium | Up to 16GB | Web/iOS; 720p above 2 hours, under 4 hours |
Size and duration are separate requirements. A video below 512MB can still exceed the 140-second standard-post limit. Trim when needed and check Premium eligibility and device-specific requirements in the upload screen.
Documentation checked on 6 October 2026. Requirements can change; also check the destination upload screen. ClipForge target size is an estimate: verify the saved size, duration and format before sending.
Reference documentation
Steps
- Select videos in ClipForge and choose local or server conversion.
- Match the container, codec, resolution and video and audio settings to the destination.
- Check a short trial for sound and picture, then save the result.
File selection screen
Prepare a copy for its destination
Start with the error message and current official requirements. Before uploading the converted file, check readable text, audio sync and whether the ending you need is still present.
Settings and checks
Check the upload error shown by X. Use MP4 with H.264 and a practical resolution.
Where processing happens and device limits
Local conversion does not send files to the conversion server. Choosing server conversion uploads them. Local conversion supports up to 512MB; server conversion supports a combined selection up to 64GB. Memory and input codec support can cause failures even below these limits.
Troubleshooting
If playback fails, check the codec inside the MP4 container too. If size exceeds the limit, review bitrate, resolution and duration. After changing fps, inspect motion, synchronization and playback through to the end.
Frequently asked questions
Is specifying only target size or resolution enough?
No. Bitrate, duration, fps and codec affect size and quality even at the same resolution. Include audio in the size budget and inspect the exported size and playback.