The replacement does not match motion
Use a source video with a clear single subject and less occlusion.
MODEL
CHARACTER ORIENTATION
Need a first successful run?
REPLACEMENT CHARACTER IMAGE
JPEG, PNG, JPG, WEBP · max 10MB
SOURCE VIDEO
MP4, MOV · max 100MB · 3-30s
PROMPT
Resolution
TOTAL CREDITS
Upload video first
Replace Character demo video
Start a generation to see your latest videos here.
CHARACTER REPLACEMENT AI
Quick answer
Replace Character uses a replacement character image and a source video. The source video provides motion and framing, while the character image guides who should appear in the result.
Input requirements
Match the source type to a conservative first motion target. That improves the keeper rate before spending credits on longer clips.
| Input | Best for | Avoid |
|---|---|---|
| Replacement character image | Clear full-body or upper-body subject with readable face and outfit | Tiny, cropped, or heavily obscured subjects |
| Source video | One visible subject, clean movement, 3-30 seconds | Fast cuts, occlusions, or multiple similar characters |
| Prompt | Short preservation notes for outfit, lighting, or realism | Asking for a different action than the source video |
Failure reasons
Use a source video with a clear single subject and less occlusion.
Upload a clearer character image and keep the prompt focused on preservation.
Upload a source video first so duration-based credits can be calculated.
FAQ
Best results come from short videos with one clear subject and stable motion.
A prompt is optional, but short notes help preserve style, lighting, or outfit details.
Motion-control credits depend on source video duration, so the estimate updates after upload.
Related pages
Transform an existing clip while preserving source timing and motion.
Open video to videoIMAGEAnimate one still image when you do not have a source video.
Open image to videoPHOTOAnimate a single photo with a simpler photo-first workflow.
Open photo to video