From picking a template to downloading the MP4 takes about a minute.
Choose one of the 12 templates on the home page. Each time you open one, it starts with a new random seed, so you get a different video.
Don't like this run? Press the dice next to the seed field to get a new one.
Change gravity, bounciness, duration and ball count. The simulation updates in under a second.
The video plays right away. Drag the timeline to check any moment frame by frame.
Download it as 9:16 (Reels, TikTok, Shorts) or 16:9 (YouTube) at 60 fps. A 30 second video takes about 10 seconds.
The same seed and settings always give the same video, so you can export it again in another format.