Hands, fast moves and crowds are the hardest parts of an AI video swap, because they are where the AI sees the least clear detail. They don't stop a swap, but they are where a frame or two can look odd: fingers that blur together, a face that flickers during a quick turn, or the wrong person getting a face in a busy scene. Pick a calmer part of the clip, check it with the free preview, and expect that some clips need another take.
Why are these three things hard for AI?
An AI person swap is generative: it learns what someone looks like from a photo and then redraws them in every frame, following the original moves, camera, lighting and sound. It does that best when the face is large, sharp and steady for a good share of the clip.
Each of the three breaks that in its own way:
- Hands have many small parts that overlap, move quickly and often blur in the original footage.
- Fast moves and a moving camera change the angle of the face from one frame to the next and add motion blur, so there is less clean detail to follow.
- Crowds put many small faces close together, and the AI has to keep track of who is who as people cross in front of each other.
This is not frame-exact editing, so nothing here can be set by hand. What you can control is the clip, the part of it you choose and the photos you give.
What can go wrong with hands?
The hands move as the original person's do, so the risks come from the scene:
- Quick gestures. Waving, clapping or finger snaps can come out with blurred, merged or extra-looking fingers for a moment.
- A hand across the face. Someone rubbing their eyes, covering a laugh or adjusting their hair hides the face, and the frames around it are a typical spot for a glitch.
- Things held in the hand. A phone, a glass or a microphone can change shape slightly while it moves.
What helps: a part of the video where the hands stay away from the face and the gestures are not too fast. For other things in front of the face, see glasses, hats and masks in an AI video swap.
What about fast moves and a shaky camera?
Dance trends, sports moments and action scenes are popular for a reason, and many of them work well. The tricky moments are:
- Spins and fast head turns. When the face is seen from the side or the back for a few frames, the likeness can come and go.
- Whip pans and shaky handheld footage. Motion blur leaves less of the face to work with.
- Jumps and cuts. A sudden change of angle can make the swapped face look slightly different before and after.
What helps: choose a part where the face is turned to the camera for most of the time, with a fairly steady camera. The result keeps the source's frame rate, up to about 30 fps, so a 60 fps clip comes out at about 30 fps.
How do crowds and groups affect a swap?
When you open a video, vswp finds the people in it and makes a card for each. Main people come first; people seen briefly or far away are grouped as the background. People who appear very briefly or are heavily blurred may not be found at all.
In a busy scene, a few things go wrong more often:
- A photo on the wrong card. Two people in similar clothes are easy to mix up. Play the clip and compare each card's picture before you add photos.
- People crossing in front of each other. When two faces overlap, the swap can briefly drift between them.
- A target who is tiny in the frame. A face that stays small changes very little when it is replaced.
A video takes up to 6 different photos, and everyone without a photo stays as in the original. Our guide on who gets swapped in a video explains the cards and the background group.
How do you check a tricky clip before you pay?
- Choose the part. In a long video, pick up to 30 seconds with the fewest hard moments. Our guide on picking the best 30 seconds shows how.
- Use sharp photos. One person per photo, face fully visible, in good light, as JPEG, PNG or WebP.
- Make the free preview. It shows about 5 seconds at 480p where the people with photos are on screen, with a small "vswp.app" mark. Watch the hands and the turns closely.
- Make the full video at 480p or 720p. The app shows the estimated time and the price first.
- Make another take if needed. Pressing "Create video" again makes a new take, which is a new render; each one comes out a little different.
If the face itself is the problem, see what to fix when an AI face swap doesn't look like you.
When is it better to pick another video?
If the person you want to replace spins for the whole clip, hides their face behind their hands most of the time, or is one small face in a packed crowd, a different clip will usually give a better result than more takes. Our guide on how to choose a video for an AI swap lists what makes a clip easy.
Prices are in Telegram Stars (⭐) and depend on the length, the quality and the number of people; the exact price is shown before you start, and Stars are returned automatically if a render fails or is canceled. Use only videos and photos you have the right to use, and ask before you use someone's photo.
FAQ
Why do the hands look strange in my AI video?
Hands move fast, overlap and are often blurred in the original, so the AI has little clear detail to redraw. A calmer part of the clip or another take usually helps.
Can I tell the AI to fix the fingers?
No. It's generative AI, not frame-exact editing, so you can't adjust single frames. Make another take or choose a part where the hands move less.
Do dance videos work?
Yes, many trends are dances. Fast spins and head turns are the moments most likely to need another take, so check them in the free preview.
Can I swap one person in a crowd?
Yes, if that person has a card. Put a photo on their card and leave the rest empty; people seen very briefly or heavily blurred may not be found.
Will a 60 fps video stay at 60 fps?
No. The frame rate follows the source up to about 30 fps, so a 60 fps clip comes out at about 30 fps.