Free, in your browser
Terrarium simulator
Glass Jar Garden is a terrarium simulator and builder that runs in your browser. Build a jar layer by layer, plant real species, seal it, and watch it live: the water cycling, moss creeping, plants growing, and mould when something is off.
Build it like a real one
- Pour drainage, a barrier, soil and a top dressing from a scoop; shape the ground with a brush.
- Plant from 49 real plants and 31 mosses, set stones and wood, and add springtails and isopods.
- Water by the millilitre, choose the light, the room and a care routine.
- Round jars, bottles and cloches fill along their curved glass.
Then it lives
Seal it, or leave it open, and every day the simulation works out the water in each layer, the humidity under the lid, the light each plant gets and its health. Before you seal, a one-year forecast says what should still be alive. How it works has every mechanism and the numbers it runs on.
A terrarium game, and a planner
It plays like a calm building game: no score, no timer, nothing to unlock. Jars keep living while you are away and catch up when you come back. It is also a planner: try a build before buying anything, then follow its recipe.
Start from a ready jar
Beginner jareasy
Moss jareasy
Paludarium litehard
Carnivore bogmedium
Desert bowleasy
Cloche gardeneasy
Wardian casemedium
Mini forestmedium
Questions
- Is it free?
- Yes. It runs in your browser, with no account and nothing to install.
- Does it work on a phone?
- Yes, on any recent phone or computer with a browser that supports WebGL.
- Is the simulation realistic?
- It runs day by day on real species data, and 14 real jars described by their owners were rebuilt in it: all 14 turned out the way the real ones did.
- Can I share my terrarium?
- Yes. A share link shows the jar as it is now, still living, and you can record a timelapse of its whole life or take photos.
- Can I use it to plan a real terrarium?
- Yes. Every starter jar has a recipe page with the glass, each layer, plant and moss, and the water and light to give it.
Interested in the science? Read about the closed ecosystem it simulates.