How to recreate a viral video with AI: what stays, what it costs, and when it is not worth it

Search for how to recreate a viral video with AI and you mostly get face swap apps: upload a video, upload a photo, done. Almost nobody tells you what stays from the original, what happens to the sound, what each second costs, or when something else is cheaper.

In Hook Studio this is called a recast. This guide comes from how it works inside the app: its limits, its prices, and the rules it applies. Everything below is how the app behaves as of October 25, 2026.

A face swap changes only the face. The body, hair, clothes, and skin still belong to the original person, which is why the edge of the face and the neck sometimes give it away. A recast replaces the whole person. You give it 1 to 8 reference images, in the order the people appear in the video, and the model generates the video again with them.

1. 1Paste the link. Paste a TikTok or Instagram link in the chat. The import costs 5 credits and takes 10 to 60 seconds. The agent sees the video's frames and the post caption.
2. 2Trim to the moment. A recast takes 15 seconds at most, so the agent first trims the part that matters. Trims are free and instant. A video under 4 seconds is billed as 4.
3. 3Pick who goes in. A saved avatar, a still you already made in the session, or a photo of a real person. Before it uses a photo you uploaded, the app asks whether you have that person's consent.
4. 4Approve the price. Nothing expensive starts on its own: the agent shows a card with the price in credits and waits for your approval.
5. 5Add the text and render. The hook text, the captions, and the end card go over the recast in the final render, which costs a few credits.
6. 6Export. You get the video, the cover, and a caption with hashtags.

One thing we learned along the way: in our cost guide we recommended a cheap draft before the final. For clips and recasts we no longer do that. A 480p draft costs less than half, but it is a different take, so the final never looks like the draft you approved. The agent now makes the recast at final quality and makes a draft only when you ask for one.

A recast charges for every second of the trimmed video. These are the prices in credits, and what they come to on the Concept plan, which gives 2,300 credits for $20 a month.

Add 5 credits for the import and a few for the render. A 10 second final recast uses half of a month's credits on the Concept plan. Per second, it is the most expensive step in the app. A 480p draft costs a little under half (271 credits for 5 seconds), but as we saw above, the final will not look like it.

Per second, a recast costs about 6 times as much as a clip made from a still. The question is not whether you can recast a video. It is whether the original hook depends on something a prompt cannot describe.

Recast when the hook is the motion

• A dance or a routine, where every move lands on a beat.
• A transition: an outfit change, a hand cut, or a camera spin.
• A physical gag with exact timing, like something falling or someone walking into frame.
• Two or more people reacting to each other.

Copy the format when the hook is the idea

Most viral videos do not go viral because of the motion. They go viral because of the idea: a "then vs now", a day in the life, a POV caption over someone looking at the camera. Nobody owns that idea, and a still and a short clip recreate it.

These prices leave out the automatic realism checks, a few credits each. Even so, the gap is 4 to 5 times per hook. If your hook fits in one sentence, copy the format. We wrote more about that in copy viral formats.

The best video to recast is one of your own

• A video of yours that already worked. Recast it with another person and test whether the same hook works for another audience, without shooting again.
• A UGC video you bought. If your agreement with the creator allows it, a recast gives you variations with other people.
• A video whose creator gave you permission. Get it in writing.

A recast comes back with the original sound as it is. That is good for a dance, where the motion is tied to the beat. It is a problem when someone talks in the video: their voice is still there, coming out of your person's mouth.

• If it is music: mute the video (free) and add the same sound from the TikTok or Instagram library when you post. That way the platform handles the license. On TikTok, business accounts can use only the Commercial Music Library.
• If someone talks: do not post another person's voice as yours. Mute the video and add your own voiceover, or make a new voice line (5 credits) and lip-sync the recast to it (71 credits per 5 seconds) so your person says your words.
• If the video has no sound: the recast comes back silent, and you add any audio you want.

• More than 15 seconds. The model takes up to 30, but we cap it at 15 because of the price. A longer video is trimmed first.
• 1080p. A recast comes out at 720p. Generated clips come out at 1080p.
• More than 8 people. You give it 1 to 8 references, in the order they appear.
• A new setting. The background, the light, and the props stay as in the original. If you want another place, that is not a recast but a new clip.
• Famous people. The agent does not put a famous person in, even if you have a photo.

• Only videos you have the right to use. Your own video, one you bought or licensed, or one whose creator gave you permission. A recast keeps the camera, the setting, and the sound of the original, so it is still largely someone else's video.
• Only people who consented. Avatars, stills you made in the app, or photos of real people who agreed.
• No famous people, and no posing as someone else.
• An AI label on every video. TikTok and Instagram ask you to label realistic AI-generated content.

A recast is one of the formats in the Hook Studio chat. You paste the link and pick the person, and the agent trims, shows you the price, waits for your approval, and builds the reel with the text on top. When the hook does not need a recast, the agent offers the cheapest path that works: a still and a short clip.

Before you recreate a viral video with AI, ask what made it work. If it was the motion, a recast keeps all of it for about $5 per 5 seconds. If it was the idea, copy it with a still and a clip for a fifth of that. Either way, start with a video you have the right to use.