Worldsmith
Worldsmith is a free, open-source browser tool for generating fantasy world maps from a numeric seed, with a separate mode for rendering Earth.
What Worldsmith is
Worldsmith is a free, open-source browser tool for generating fantasy world maps from a numeric seed, with a separate mode for rendering Earth. It produces terrain using domain-warped fractal noise, including ridged mountain ranges, and derives biomes from elevation, moisture, and temperature. Rivers use D8 flow accumulation to form drainage networks. Exports include PNG maps up to 5120 px, editable SVG maps up to 3840 px, JSON world data, and 8-bit or 16-bit heightmaps. The maker says the heightmaps can be imported into Unity, Unreal Engine, Blender, and World Machine. Earth mode uses NOAA ETOPO1 elevation and bathymetry, averaged to about 5 km per sample; synthesized detail is disclosed in the interface and can be disabled by setting Detail to 0. Worldsmith runs client-side without an account, server, or dependencies and is available under the MIT license. The maker notes that the climate model omits monsoons, ocean currents, and mountain-specific rain shadows, and that rivers may not remain globally consistent when panning.
Good
- Free and open source under the MIT license
- Generates maps from a numeric seed
- Exports PNG, editable SVG, JSON, and heightmaps
- Heightmaps are suitable for listed game and 3D tools
- Runs client-side without an account or server
Watch out
- Climate model omits monsoons and ocean currents
- River drainage follows the visible grid when panning
- Older phones may struggle with the Earth heightmap
- Firefox and Safari are untested
Who it suits
Worldsmith suits people who want seeded fantasy maps or Earth terrain data to export into image, vector, data, or heightmap formats. Its browser-based client-side operation may also appeal to users who do not want an account or server dependency.
Verdict
Worldsmith offers seeded fantasy map generation, Earth rendering, and several export formats in a client-side browser tool. Be aware of its stated climate and drainage limits, along with untested Firefox and Safari support.
Plans and prices
From Worldsmith's own pricing page, checked 8 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Free | Free | Free and open source under MIT license · no account, server or dependencies |
The facts
Each one read from Worldsmith's own pages, with the date it was checked.
What it does
- Accessibility limitation
- The maker says the rendered canvas cannot be made readable by assistive technology, though controls are keyboard-operable and labelled.checked 8 Oct 2026
- Client-side operation
- The maker says the app runs entirely client-side with no account, server or dependencies.checked 8 Oct 2026
- Climate limitation
- The maker says its climate model does not account for monsoons, ocean currents or mountain-specific orographic rain shadows.checked 8 Oct 2026
- Data disclosure
- The maker says synthesized terrain detail in Earth mode is disclosed in the interface and can be disabled by setting Detail to 0.checked 8 Oct 2026
- Earth data
- Earth mode uses NOAA ETOPO1 elevation and bathymetry, box-averaged to about 5 km per sample.checked 8 Oct 2026
- Exports
- It exports PNG maps up to 5120 px, editable SVG maps up to 3840 px, JSON world data, and 8-bit or 16-bit heightmaps.checked 8 Oct 2026
- Hydrology limitation
- The maker says drainage is solved on the visible grid, so rivers may not remain globally consistent when panning.checked 8 Oct 2026
- Integrations
- The maker says heightmaps are suitable for import into Unity, Unreal Engine, Blender and World Machine.checked 8 Oct 2026
- Limits
- The maker says the Earth heightmap is about 27 MB and decodes to a roughly 67 MB resident grid, which may challenge older phones.checked 8 Oct 2026
- Purpose
- Worldsmith generates infinite fantasy world maps in a browser from a numeric seed and can also render real Earth.checked 8 Oct 2026
- Rivers
- Rivers are computed using D8 flow accumulation so tributaries merge into drainage networks.checked 8 Oct 2026
- Security and network behavior
- The maker says shipped files have no runtime dependencies or network primitives, and its smoke tests check that the page makes no external requests.checked 8 Oct 2026
- Terrain and climate
- Generated terrain uses domain-warped fractal noise with ridged mountain ranges, and biomes are derived from elevation, moisture and temperature.checked 8 Oct 2026
Where it runs
- Browser verification
- The maker says the project is verified on Chromium, while Firefox and Safari are untested.checked 8 Oct 2026
The company
- Founded
- 2026checked 28 Sep 2026
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