Mapgen4
Mapgen4 is a free procedural wilderness map generator from Red Blob Games.
What Mapgen4 is
Mapgen4 is a free procedural wilderness map generator from Red Blob Games. Choose a seed, paint mountains, valleys, and oceans, and the simulation uses evaporation, wind, and rainfall to shape biomes and rivers. Sliders let you adjust simulation and style settings, including rainfall and river flow. The map renders terrain in 3D with a custom projection and outline for a hand-drawn-inspired appearance. You can download a high-resolution PNG and use maps you create as you wish; credit is appreciated but not required. Mapgen4 runs on the web, and its source code is available for local browser use, with build instructions for npm or pnpm. The code and helper libraries use the Apache v2 license, including for commercial projects. The maker describes the project as finished and mostly inactive, with code changes in April 2023. Rendering parameters are designed for about 25,000 Voronoi cells, though the underlying code supports more than one million. The page notes that the tool does not work on all platforms.
Good
- Free to use on the web
- Seed control and terrain painting
- Simulation generates biomes and rivers
- High-resolution PNG download
- Apache v2 license permits commercial projects
Watch out
- Does not work on all platforms
- Project is finished and mostly inactive
- Rendering settings are designed around 25,000 cells
Who it suits
Mapgen4 suits people who want to create procedural wilderness maps by painting terrain and tuning simulation settings. Its source code and commercial-use license may also suit independent, student, and hobbyist developers.
Verdict
Its finished, mostly inactive status and platform limitations are worth considering before choosing it.
The facts
Each one read from Mapgen4's own pages, with the date it was checked.
What it does
- Audience
- Red Blob Games says its main audience is independent, student, and hobbyist software developers.checked 2 Oct 2026
- Code license
- Mapgen4 and its helper libraries are licensed under Apache v2, and the maker says they can be used in commercial projects.checked 2 Oct 2026
- Controls
- Sliders let you change the simulation and map style.checked 3 Oct 2026
- Download and local use
- The repository provides the source code and instructions to build it with npm or pnpm and run it locally in a browser.checked 2 Oct 2026
- Export
- The page offers a high resolution image download and says it does not work on all platforms.checked 3 Oct 2026
- Export and usage
- The page offers a high-resolution image download and says users may do as they please with maps they create; credit is appreciated but not required.checked 2 Oct 2026
- Limits
- The README says the code can support over one million Voronoi cells, while rendering and other parameters are designed to look best around 25,000 cells.checked 3 Oct 2026
- Local use
- The README gives build instructions and says to run a local HTTP server and visit embed.html in a browser.checked 3 Oct 2026
- Project status
- The maker describes the project as finished and mostly inactive.checked 3 Oct 2026
- Purpose
- Mapgen4 is a procedural wilderness map generator.checked 3 Oct 2026
- Security and compliance
- The opened Mapgen4 page and repository do not state any security or compliance certifications.checked 2 Oct 2026
- Simulation
- The generator simulates evaporation, wind, and rainfall to determine biomes and rivers.checked 3 Oct 2026
- Source code
- The source is available on GitHub, and the README says Mapgen4 and the maker's helper libraries are licensed under Apache v2 for use in commercial projects.checked 3 Oct 2026
- Style
- Its 3D rendering uses a custom projection and outline intended to give the map a hand-drawn look.checked 3 Oct 2026
- Support
- The Mapgen4 page invites users to email the maker or comment on the page.checked 3 Oct 2026
- Terrain editing
- You choose a starting seed and paint mountains, valleys, and oceans on the map.checked 3 Oct 2026
- Terrain style
- It aims for a hand-drawn-inspired look, rendering terrain in 3D with a custom projection and outline.checked 2 Oct 2026
- Unbuilt features
- The maker lists drawing rivers, sphere output, resources, towns, forests, names, roads, and nations as features that could be added in a future project.checked 2 Oct 2026
- Usage rights
- The maker says anything created with the tool is yours to use as you please, and credit is appreciated but not required.checked 3 Oct 2026
The company
- Founded
- 2018checked 28 Sep 2026
- Maker
- Red Blob Games identifies Amit Patel as its maker and says he makes interactive visual explanations of math and algorithms.checked 3 Oct 2026
Money
- Planned omissions
- The maker lists drawing rivers, sphere output, natural resources, towns, forests, names, roads, and nations as features left for a future project.checked 3 Oct 2026
Alternatives to Mapgen4
- 1
World Machine
Free planLinuxmacOSWindows7.6$119 one-time - 2
Heightmap Level Generator
Free planOpen sourceWebSelf-hostedWindows7.2Free plan - 3
Gaea
Free planWindows6.8$99 one-time - 4
Infinity Generation
Free planAPILinuxmacOSWindows6.8Free plan - 5
Voxel Plugin
Free planAndroidmacOSWindows6.8$349 one-time - 6
L3DT
Free planLinuxWindows6.7$34.95 one-time