Seedance Character Swap: Replace a Character, Keep Every Shot

A Seedance character swap puts your character in place of the lead in an existing video. The shots, cuts, camera moves and timing stay where the original has them. Here is how to do it in Riffkit's Swap mode, engine by engine. A disclosure first: we make Riffkit.

What a Seedance character swap is

ByteDance's Seedance 2.5 tutorial on BytePlus lists "replacing the video subject" under video editing, for reference videos of 4 to 30 seconds. Its Seedance 2.0 prompt guide caps video input at 15 seconds in total.

Riffkit's Swap runs those engines for you. It renders the whole video again on the source's own clock, carrying the source clip into every render: up to 15 seconds per render on Seedance 2.0 and 2.0 Fast, up to 30 seconds on 2.5. A longer source is split at its shot cuts, up to 45 seconds per job. Because the video is rendered again, the setting and wardrobe can change too (face swap vs character swap vs a full reshoot).

Step 1: set up your character

1. In the web app, open Characters and tap + New character.
2. Add a name, a gender, an age range and one photo (JPG, PNG, WEBP, BMP, TIFF or GIF, up to 30 MB).
3. Use one face, front-facing, large in the frame, on a plain background. A natural photo gives more realistic videos than an over-retouched one. A collage or a sheet of poses usually fails in close-ups: the output keeps the original face and at most picks up the hair.
4. Save. The photo goes to the video platform's review, usually for under a minute, and the status turns Ready. If it reads Review failed, upload a different photo.

Use your own photo or one you have permission to use.

Step 2: replace the character in your video

1. Open Swap.
2. Add the clip: an upload up to 100 MB, a TikTok link or a template. Swap keeps the full length, up to 45 seconds, so a longer source is turned away, not trimmed. For a video you made in Riffkit, download it and upload it.
3. Pick your character. Each character makes its own video, billed on its own.
4. Optionally, write in "What to change" (more below).
5. Pick Seedance 2.0 Fast, 2.0 or 2.5 and a resolution. The per-second rate shows before anything renders.
6. Tap Riff it →. Each part of the source first passes the video platform's content review, which can take several minutes on a new clip. A refused clip costs nothing.

Seedance 2.0, 2.0 Fast or 2.5?

We recommend Seedance 2.5 for swaps, and a paid Swap defaults to it at 720p. On 2.5, narration (heard, not seen) keeps the original voice unless "What to change" asks, for example "the narration also in the new person's voice". "Keep the original audio" keeps every voice. The new voice is AI-generated. A character's saved voice sample is used in Adapt riffs and creations.

Renders bill whole seconds, rounded up (4 seconds minimum), so a split clip can bill up to 1 second more per extra render.

Write "What to change" alongside the character

The character takes the lead. Everything else goes in "What to change": a prop, an outfit, the setting, the rest of the cast. Leave it empty and only the character changes.

The example we can show here changed its cast by description, with no saved character. We reshot the 30-second STORM II clip on Seedance 2.5 at 720p as a grandma choir: grandmothers in lilac cardigans fill the crowd, and the lead becomes a grandfather holding tea where the original holds a cigarette. A 480p draft came first, at half the 720p rate; the final took about ten minutes. Lessons that carry over:

• Name the hard moments. Young faces crept back at the climax until the brief said "for the whole video, including the final frenzy".
• Tie props to actions. "Sipping it where the original takes a drag" put the tea on the cigarette's beats.
• Expect misses. The crowd never mouthed the song, in two tries.

STORM II is by GENER8ION (Surkin and Romain Gavras), starring Yung Lean, with choreography by Damien Jalet. The footage and music are theirs. Ours is a non-commercial demo, and YouTube flagged it as claimed content. The full brief is in our STORM II how-to.

Someone changed only by words has no reference image, so the face can differ between shots. A saved character gives the model a photo to work from in every shot, which is also how you keep one character steady across a series.

What stays, what changes, and the limits

• Stays: shots, cuts, camera moves, framing, poses, timing, full length, aspect ratio, language and music.
• Changes: the lead becomes your character, plus whatever "What to change" names. With no character picked, the original lead stays, real face included.
• Something has to change. A character counts only when the source shows someone to replace. A swap with nothing to change is refused before anything is billed.
• Billing. Failed renders cost nothing. If a run fails partway or you cancel, the seconds already rendered are billed.
• Sound. A render whose new sound is rejected as a copyrighted recording keeps the source clip's sound, so on 2.5 your character may speak in the original voice there.
• Rights. Swap keeps the source's music, and someone else's TikTok still belongs to them. For another creator's winner, use Adapt, which keeps the formula and makes new footage (where the line sits).

Free accounts

New accounts start with free credits, no card needed. A free account can Swap on Seedance 2.0 Fast at 480p (the default), Seedance 2.0 at 480p or MiniMax H3 at 768P. A short clip comes back whole. Most longer ones start with a free first section, and a plan finishes the rest. Seedance 2.5, 720p and 1080p come with a plan, from $15 a month for 3,000 credits.

Try it

Set up your character, then open Swap and run it on a clip of your own. In a chat instead? Replace the person in a video from Claude or ChatGPT.