About 3D Game Editor
Free 3D game world builder for kids 8+, parents, and teachers. Place trees, buildings, characters, and items with drag-and-drop, paint terrain biomes, build smart walls, then walk through what you built. No sign-up, no ads, runs offline once loaded.
How to use
- Pick an asset from the right-hand panel — categories include trees, rocks, buildings, characters, vehicles, props, and water features. Click an asset card, then click on the ground in the 3D viewport to place it. Hover over an asset card to see a 3D preview before placing. The status bar at the bottom shows your object count and current cursor position.
- Move, rotate, and scale objects using the toolbar gizmo. Press M for Move (drag the colored arrows along X/Y/Z), R for Rotate (drag the rings), or S for Scale (drag the cubes). Hold Shift while dragging to snap to whole-number increments. Click an object to select it, then use the gizmo or the Properties tab to set exact values.
- Build smart walls and fences with the Line tool (📏). Click to drop wall nodes — they auto-corner, snap to angles, and seal into closed loops when you click near the first node. Choose from five wall styles: Castle Wall, Wood Fence, Stone Fence, Hedge, or Barrier Rail. The Street tool (🏘️) drops a row of buildings along a path for instant towns.
- Paint terrain with the Paint tool (🖌️). Choose a biome — grass, sand, snow, dirt, stone, or water — and brush it onto the ground. Adjust brush radius with the slider; the dashed circle on the cursor shows your brush size. Painting water automatically lowers the heightmap so water sits at the right level. The Terrain tab lets you raise, lower, smooth, and flatten the ground.
- Use Random Generate (🎲 or F2) to fill an empty world with a balanced scattering of trees, rocks, and characters using Poisson-disk distribution — this is the same algorithm professional game studios use to avoid clumpy placement. Pick a game type from the World tab (platformer, RPG, racing, dungeon, and more) to seed the world with appropriate assets.
- Switch to Walk Mode (🚶 or press W) to explore your world in first person. Use WASD to move, mouse to look, Space to jump, and V to toggle between first-person and third-person camera. This is the best way to spot scale problems — a tower that looked tall in editor view might feel small when you're standing next to it. Press Esc to return to the editor.
- Save your world as a JSON file (💾 or Ctrl+S) — the file holds every object's position, rotation, scale, and type, plus the terrain heightmap and world settings. Click 📂 Load to upload that JSON later. Worlds save to your own device, not to a server. There are no accounts, no ads, and no data leaves your computer.
Frequently asked questions
What age is this 3D game editor for?
Designed for kids 8 and up. Younger kids (6-7) can use it with help — placing assets, painting terrain, and walk mode work with single clicks. Older kids and teens can dig into the gizmo controls (move/rotate/scale on X/Y/Z), smart walls, the street builder, and the nine game-type generators for more advanced builds. Adults use it as a quick scene-prototyping tool too.
Is the game editor safe for kids? Any sign-up or ads?
Fully COPPA-safe. No sign-up, no account, no ads on kids pages, no personal data collected. Everything runs in the browser using Three.js — once the page has loaded, the editor works offline. Worlds save as JSON files to your own device. Parents and teachers can use it in class or at home without any privacy paperwork or login chains.
How do I save my world?
Click the 💾 Save button (or press Ctrl+S) to download your world as a JSON file. The file contains every object's position, rotation, scale, and type, plus the terrain heightmap and world settings. Click 📂 Load and pick that JSON later to pick up exactly where you left off. Worlds save to your computer — you control the file, you can email it to a friend, and nothing is stored on a server.
What is walk-through mode?
Walk-through mode (press W or click 🚶) drops you into your world as a walking character with WASD movement and mouse-look camera. It's a first-person preview of what your world feels like at human scale — perfect for spotting walls that are too tall, paths that are too narrow, or houses placed too close. Press V to toggle between first-person and third-person view. Press Esc to return to the editor.
Does this teach real game-design skills?
Yes. Kids learn level design (composition, sight-lines, pacing), 3D coordinate systems (translate/rotate/scale on X/Y/Z via the gizmo), procedural thinking (smart walls auto-corner; random generate uses Poisson-disk distribution to avoid clumpy placement — the same trick AAA studios use), and iteration (build, walk through, fix, repeat). Aligns with NGSS K-2 ETS1 design-thinking practices and the engineering design cycle.
What if it's slow or laggy?
If frame rate drops in walk mode, first check that you're not on battery saver — Chrome's Energy Saver throttles all 3D graphics to 30 FPS. Plug in or disable Energy Saver. If it's still slow, the world may have too many objects (the editor handles thousands but slows on lower-end devices around ~5,000). Try removing fog details or reducing the terrain biome resolution in the World tab.
Part of ToolFluency's library of free online tools for kids. No account needed, no data leaves your device. COPPA-safe.