Edit motion is the Edit Video tool that makes a character follow the movement of a source video. You give it a source video — its motion is what the result follows — and a base image of your character when No Model mode is active, and it renders the character moving the way the video does. With a portrait model selected, that Base image remains optional.
What does Edit motion do?
It takes the motion from your source video and re-renders your character following it. This is the opposite of Edit character: Edit character keeps the motion and swaps the character, while Edit motion changes the motion the character performs.
How do I run an Edit motion edit?
Open Edit Video and pick Edit motion from the tool switcher.
Add the source video whose motion you want to use — its movement is what the result follows — with Select content or Upload video.
Add a Base image of your character; it will follow the source video's motion. This is required in No Model mode and optional when a portrait model is selected.
Adjust quality and resolution in the bottom bar if needed.
Click Generate — the cost is shown next to the button.
How do I supply the base image?
The Base image is required in No Model mode and optional when a portrait model is selected. You have three ways to add one, the same as Edit character:
Select content — pick an existing image from your Generation media (followed by curated inspiration) or Community media.
Generate reference image — create a new reference image in a built-in dialog, optionally guided by your source video.
Upload image — upload an image file from your device.
The chosen image appears in the panel with a Delete button so you can replace it.
What if I don't add a base image?
With a portrait model selected, the panel notes, "If you don't provide a reference image, we'll choose one automatically," and skipping the Base image uses that model. In No Model mode, the Base image is required; Generate stays disabled until you select, generate, or finish uploading one. Trying to continue without it shows "Please select or upload a base image." An unfinished upload shows "The image is still uploading. Please wait a moment."
Is there a length limit?
Yes. Ultra and UltraS accept a selected clip between 4 and 30 seconds; Best accepts 4–15 seconds and supports 480P, 720P, and FHD. The hint below the source-video controls updates to "Use a video between 4 and 15 s." on Best or "Use a video between 4 and 30 s." on Ultra/UltraS. A shorter clip shows "The video must be at least 4 s." If a clip longer than 15 seconds is selected on Ultra or UltraS, switching to Best is blocked with "Trim the video to 15 seconds or less before switching quality." Use the scissors (trim) button next to the duration to shorten it, then switch again. Best is powered by Seedance 2.0, while Ultra and UltraS are powered by Seedance 2.5; hover a quality on desktop, or tap its info icon on mobile, to see the model note.
Can I jump straight to Edit character?
Yes. On Edit motion the panel shows a shortcut: "To swap the character in the video, use Edit character." Tapping it switches tools and keeps your video in place.
On mobile
The flow is the same, with the source-video and base-image controls stacked vertically. Generate reference image opens as a full-screen page rather than a dialog, and pickers/uploads use full-screen sheets with progress and delete controls. In No Model mode the label is Base image without "(optional)," and the automatic-image fallback note is hidden.
Related: Edit Video overview · Edit character · Edit style