What If Video Generator
Ask a what if question and watch the answer unfold in a miniature world, like a scale model seen from above. The AI writes an event that gets worse shot after shot and follows it on site, from the sky down to the street. No voiceover and no captions: ambient sound effects and a counter in the top left corner. About 45 seconds in 9:16, ready for TikTok, Reels and Shorts.
1000 free credits when you sign up, no card required
Videos made with this tool
Natural disaster
A flood, a storm or an eruption that keeps gaining ground, with a counter that climbs: "Water +12 ft", "Wind 110 mph".
Social experiment
A thousand people on one island, a city without power: the crowd gets organized day after day, with "Day 12" on screen.
Your city, transformed
A neighborhood you know, turned into a scale model, then turned upside down by your scenario. The place stays the same from the first shot to the last.
A series for your channel
A new question in every video, the same style every time: a recurring format people recognize in the first second.
How to make a what if video with AI
- 01
Ask your what if question
A place and an extreme event: "What if the sea rose 30 feet in Miami". You can also describe the place in a few words to frame the setting.
- 02
Keep the isometric look or switch styles
The isometric style, like a diorama or a city builder game, is set by default. You can pick another visual style before launching.
- 03
Check the cost and launch
The cost is shown before you launch. The AI writes the escalation, generates each shot as a continuation of the previous one and adds the sound effects.
- 04
Download and post
You get a vertical MP4 of about 45 seconds, with its on-screen counter, ready to post on TikTok, Reels or Shorts.
What this AI simulation video generator does
A miniature world
Your question becomes a scale model seen from above, with its streets, buildings and crowd, in isometric style by default.
Escalation, shot after shot
Each moment is worse than the last. The event is followed on site and from place to place: aerial view, street level, first person.
A place that stays the same
Each shot picks up from the image of the previous one. Buildings and landmarks stay where they are while the event moves forward.
The sound of the place, no voiceover
Waves, crowds, sirens: the sound effects are generated with the video. Nobody talks, the picture tells the story.
A counter, and nothing else
A big number and its label in the top left corner, like "Sea level +10 ft" or "Day 12". No captions covering the picture.
The same style from one video to the next
Create a simulation series: every new question keeps the series style, for a recurring format on your channel.
Who this what if video generator is for
Science and explainer channels
Make a science or geography question visible in 45 seconds, without 3D software or stock footage.
Faceless creators
Post a format that works with the sound off and no face on camera, with a new question in every video.
Teachers and trainers
Open a lesson on climate, cities or population with a scenario the class watches unfold.
Local media and city pages
Ask a question about your city and show it as a scale model: a format that speaks to the people who live there.
Rewatch vs making a what if simulation by hand
| What you need | With Rewatch | By hand |
|---|---|---|
| Setting | A miniature world generated from your question | Modeled in 3D, building by building |
| Scenario | An escalation written to build shot after shot | A storyboard you write yourself |
| Continuity | Each shot picks up from the previous one | Matching shots checked by hand |
| Sound | Ambient sound effects generated with the video | A sound library synced track by track |
| On-screen text | A counter in the top left corner, included | Animated in motion design |
| Cost | Shown before launch | Software, render time and working hours |
What is an AI simulation video?
A what if video shows a hypothetical scenario as if you were there: the sea rising, a city emptying out, an island filling up. On TikTok and YouTube Shorts the format works because it answers a question everyone has wondered about, in pictures, with a climbing number to give a sense of scale.
With Rewatch, you type the question and the AI writes the event, draws it as a miniature world and animates it shot by shot, each shot continuing the previous one. It is not a physics engine: the numbers are chosen to be plausible and consistent with each other, not calculated. It is an entertainment and explainer format, not a forecast.
Frequently asked questions
Every other Rewatch tool
Stories and fiction
AI Story Video Generator
Type a story idea, get a finished vertical video with characters, voices and captions.
Try itAI Short Drama Generator
Turn a one line premise into a vertical drama episode with recurring characters.
Try itAI Movie Maker
Make a short cinematic film from text: script, cast, voices, camera and edit.
Try itAI Anime Video Generator
Create anime style story videos from a single idea, ready for TikTok and Shorts.
Try itAI Cartoon Video Generator
Make cartoon videos in flat, 3D, chibi or comic styles from a simple prompt.
Try itCreepy Horror Story Generator
Write and animate scary stories with slow tension, dark visuals and a final twist.
Try itAI True Crime Video Generator
Narrate mysteries and investigations as moody, documentary style short videos.
Try itAI Fruit Drama Generator
Write and animate viral fruit drama: glossy 3D fruit characters with real dialogue.
Try itConsistent Character Video Generator
Keep the same face, outfit and voice on every shot and every episode.
Try itAI Character Generator
Describe a character or upload an image: a portrait and two angles, reusable with @Name.
Try itAI Series Generator
Build a TikTok series: a locked cast, each episode picks up the last, with an autopilot.
Try itRealistic AI Video Generator
Photorealistic videos from one idea: real looking faces, voices and captions.
Try itAI Motivational Video Generator
Cinematic motivational shorts with a deep narrator voice and a rising arc.
Try it
Brainrot
Italian Brainrot Video Generator
Absurd Italian brainrot characters, native voices and chaotic stories in one click.
Try itText to Brainrot
Paste any text and turn it into a fast, absurd brainrot story video.
Try itFrench Brainrot Generator
Brainrot videos voiced in French, with absurd characters and tight pacing.
Try itSpanish Brainrot Video Generator
Brainrot videos voiced in Spanish, from meme characters to chaotic plots.
Try itGerman Brainrot Video Generator
Brainrot videos voiced in German, with absurd characters and tight pacing.
Try it
Faceless and automation
AI Faceless Video Generator
Grow a channel without a camera: script, visuals, voices and captions done for you.
Try itAI Video Generator
Turn an idea, an image or a TikTok link into a complete vertical video.
Try itText to Video AI
Type a sentence, get a narrated and animated video with captions.
Try itPrompt to Video
Describe the video you want in a prompt and get a finished edit.
Try itImage to Video AI
Upload a photo, describe the motion: AI animates it into a vertical clip.
Try itScript to Video
Paste your script and dialogue, every line is spoken word for word.
Try itClone Video with AI
Paste a TikTok link and remake it in your style, with characters and voices kept.
Try itYouTube Automation Tool
Run a faceless series: same cast and universe, a new episode every time.
Try itLong Form AI Video Generator
Turn one idea into a narrated story of 3 to 10 minutes, written in chapters and assembled into one vertical video.
Try it
Social formats
AI TikTok Video Generator
Make TikTok videos from an idea or a link, captioned and ready to post.
Try itAI YouTube Shorts Generator
Make story driven YouTube Shorts with a strong hook and clean captions.
Try itAI Reels Maker
Create Instagram Reels from a single sentence, in the visual style you pick.
Try itAI ASMR Video Generator
Calm, slow and soft spoken story videos for relaxing vertical content.
Try itTikTok Thumbnail Generator
Generate striking story stills and a ready TikTok cover with your video's title.
Try itYouTube Thumbnail Generator
Generate cinematic stills of your characters to build thumbnails from.
Try itTikTok Virality Score
Score your script out of 100 before posting, with the 3 fixes worth the most points.
Try it
Ads and UGC
UGC Ad Generator
Phone style ads: a realistic person presents your product to camera, with demo shots and a call to action.
Try itAI UGC Video Generator
A realistic person talks about your product to camera, with demo shots and captions, without a shoot.
Try itAI Avatar Video Generator
Write your text and a realistic talking avatar says it to camera, lips in sync, with captions.
Try itTalking Photo AI
Make a photo of a person talk: your text said to camera, lips in sync.
Try it
Education and documentary
Music and audio
AI Music Video Generator
Upload your song and tell its story: every sung line becomes a shot, cut to the beat.
Try itAnimated Lyrics Video Generator
Every sung line illustrated, with your lyrics on screen word by word as they are sung.
Try itAI Music Video with Visualizer
Turn your song into a 9:16 music video: every shot illustrates the sung lyric, cut to the beat, with an optional audio visualizer and lyric subtitles.
Try it
Your what if question, as a miniature world
Type your question, keep the isometric look or switch styles. Rewatch makes the event escalate, shot after shot.