Falling Sand Simulator

A sandbox where the screen is a grid of tiny cells and each cell is a material. Simple rules for each material, such as sand falls, water flows, fire rises and burns, add up to rich behaviour: dunes, waterfalls, wildfires and chemical reactions.

Yes. It is free with no sign-up and no watermark on your pictures or videos. It runs in your browser, with nothing to install.

Powders: sand, salt, snow, soil, mud, ash, coal, gunpowder and seeds. Liquids: water, oil, acid and nitro. Gases: steam, smoke and gas. Solids: walls, stone, wood, metal, ice and glass. Fire and energy: fire, lava and sparks. Life and special: plants, clone and void, plus the eraser. Salt water and embers appear through reactions.

Fire lights wood, coal, oil, plants, gas, gunpowder and nitro; water puts fire out and turns to steam; steam rises and rains back down as water; lava turns water into steam, cools into stone and melts sand into glass; salt dissolves in water; acid eats almost everything except glass and walls and is used up doing it; seeds sprout on wet ground; sparks run along metal and set off whatever touches it.

Press Record, play and draw as usual, then press Stop. Choose the time-lapse speed, video shape (9:16, 1:1 or 16:9), resolution and frame rate, and export an MP4 (or WebM in browsers without MP4 encoding). The video is rendered from the recording, so it is perfectly smooth even if your device was busy.

Yes. Save scene downloads a small file you can open again later or share with friends. Save PNG keeps a crisp picture of the world.

Yes. Open a PNG or JPG and each pixel becomes the material with the nearest colour, then press Play and watch it crumble, flow and burn.

Yes. Draw with your finger, pick materials from the toolbar and use the Vertical 9:16 world size for clips that fill a phone screen.

Yes. Press the Gravity button or G and everything falls the other way: sand piles up on the ceiling and smoke sinks to the floor. Press it again to flip back. Time-lapse recordings keep every flip.

Clone copies the first material that touches it and keeps making more, so it works as a tap for water, sand or lava. Void removes anything that touches it, which makes a handy drain.

Type in the search box above the elements, or press / and start typing. The group buttons show one kind of element at a time, and hovering an element shows what it does.