Voronoi Map Generator
Create a bounded diagram from up to 30 clicked seeds and download GeoJSON. Cells use planar longitude/latitude degrees, not geodesic or road distance.
By Aryan Khan, Founder & Editor · Updated October 2026
The diagram uses longitude and latitude as flat degrees, not geographic or road distance.
How to use Voronoi Map Generator
Every point on the map gets assigned to its nearest seed:
Click up to 30 seeds to generate cells clipped to a padded rectangle and download GeoJSON. Distances are calculated in longitude/latitude degrees, so cells are not reliable geodesic or drive-time catchments.
- 1Click the map to add seed points.
- 2Watch the cells form as you add points.
- 3Download the diagram as GeoJSON.
What people use Voronoi Map Generator for
1. Service territories and franchises
Nearest-site territories with no overlaps and no gaps — the defensible first draft of a territory map, refinable later with roads and drive times (the Drive Time Map shows the road-shaped truth).
2. Facility planning
Where does the next clinic or depot relieve the most pressure? The largest, most stretched cells point at the answer.
3. Coverage analysis
Warehouses, towers, stores: the cell shapes expose which neighbourhoods are far from every seed — the Store Locator Map Builder's list becomes this map directly.
4. Teaching geometry
Perpendicular bisectors you can see: every cell edge is the set of points equidistant from two seeds. Voronoi is the rare maths topic that explains itself in one picture.
Worked examples
Hartford is closer to Boston (92.4 mi) than to New York (100.4 mi) as the crow flies, so it wears Boston's colour — despite every cultural instinct saying otherwise. Straight-line territory is honest about distance and blind to highways; both halves of that sentence matter.
Between two seeds, the cell border is the perpendicular bisector of the segment joining them: every border point is exactly equidistant from both. Move a seed and the whole neighbourhood's borders swing — the map is a machine for what-if.
Reading a Voronoi map
What the picture claims — and what it does not.
| You see | It means | It does not mean |
|---|---|---|
| A cell | Ground nearer this seed than any other | That people actually travel this way |
| A straight border | Equidistance from two seeds | A road or a legal boundary |
| A huge cell | A seed alone with a big area | A problem — sparse areas deserve big cells |
| A tiny cell | Seeds clustered tightly | Inefficiency — cities cluster on purpose |
Examples are conceptual; the tool uses degree-space distances and a bounded rectangle, not guaranteed geographic nearest areas.
How to interpret the result
The most common errors come from using a correct result to answer the wrong geographic question. Keep these points in mind for Voronoi Map Generator:
- Choose colour for category, not decoration: two or three high-contrast hues read instantly; a rainbow reads as noise. Labels carry identity, colour carries grouping, and the viewport should crop tightly to the subject.
- Export twice: an image for the slide and a data format (GeoJSON/CSV) for the record. The image communicates; the data survives editing, and the pair keeps your map honest and reusable.
Limits & appropriate use
Custom maps inherit two honest limits: the basemap's and the message's. The basemap is OpenStreetMap's current picture with its ODbL attribution ask, and its gaps — new roads, thin rural detail — travel into every export that includes tiles. The message limit is design's classic one: a map can carry one argument well, and beyond a few dozen symbols the right instrument changes to data-driven mapping with clustering and categories. Both limits are stated where they matter, because the alternative is a beautiful figure that misleads its own author.
Within those bounds the workflow is complete and durable: pins, labels, colours, tight framing, pixel-ratio PNG for the slide, GeoJSON/CSV for the record, URL-state for the living version. Escalation is gentle by design — choropleths and territory shading belong to GIS with real boundaries (the blank-map library and GeoJSON exports feed it), cartographic print production wants vector pipelines, and brand-strict design systems want tokens this tool deliberately doesn't fake.
- Data-dense maps → CSV-to-map with clustering and category colour.
- Boundary shading/choropleth → GIS with census or OSM boundaries.
- Print cartography → vector exports into a design pipeline.
Data & methodology
Half-plane clipping of each cell against every other seed's perpendicular bisector, in the browser.
For source details, licences and model limitations, see Data Sources and Methodology.
Key terms worth knowing
- Viewport framing
- Cropping the map tightly to the subject so the message fills the frame.
- Cluster marker
- A grouped dot representing many nearby points at low zoom.
Editorial guidance: MapBench explains the method and limitations so the tool can be used as a transparent reference, not as a black-box answer. For legal boundaries, safety-critical routing, surveying, engineering, regulated decisions or official statistics, verify the result with the responsible authority or a qualified professional.
Category: Map Creation. Results are intended for everyday analysis and planning unless a page explicitly states otherwise.
Method, assumptions & limits
- This tool’s method
- Half-plane clipping of each cell against every other seed's perpendicular bisector, in the browser.
- Before relying on the answer
- Inspect the labels, map extent and export options in the workspace. Test the exported or shared version rather than assuming it matches your current screen.
- What the result cannot establish
- Map styling does not verify a location or grant rights to third-party data. Keep attribution with any reused basemap or dataset.
Coverage: Worldwide. Search, basemap and external data requests may use third-party services; browser-based does not mean every operation is offline. Read the source and licence notes, calculation methodology and privacy policy. If a result looks inconsistent, report a correction with the inputs and mode used.
Frequently asked questions
Clear answers about the calculation, accuracy and appropriate use.
How accurate is it at large scales?
Cells use Euclidean longitude/latitude degrees, which distort distances even locally. They are clipped to a padded rectangle; use an appropriate projected or geodesic method for accurate analysis.
How many seeds?
Up to 30 — enough for a realistic territory plan without turning the map into confetti.
Can I share the map or output?
Many MapBench tools support shareable URLs or exports. Check the tool controls and the source-data licence before republishing externally.
Which export format should I choose?
Use PNG for presentation, CSV for tabular data, and GeoJSON/KML/GPX when geographic geometry needs to remain editable.
Will a shared link preserve my settings?
Tools that store state in the URL can reopen that configuration. Sensitive or private data should not be placed in public URLs.
Which distance does it use?
Euclidean distance in longitude/latitude degrees. This distorts real-world distances, including locally, and is not road or geodesic distance.
What happens with duplicate seeds?
Coincident seeds can produce overlapping cells. Remove duplicates before use.
Can cells be clipped to a custom boundary?
No. Cells are clipped to an automatically padded bounding rectangle.
Can I export?
Yes, the generated polygons can be downloaded as GeoJSON. Verify results with an appropriate GIS method before making decisions.
Related tools and resources
The seed list: the Store Locator Map Builder; road truth: the Drive Time Map; radius view: Map Radius.
More free tools
Sources, methodology & editorial trust
- ✓ Browser-first processing where supported
- ✓ External sources are documented
- ✓ No account required for public tools
- ✓ Review data sources
Calculations are documented with their assumptions, limitations and source context rather than presented as unexplained answers.
Reviewed and maintained by Aryan Khan, Founder & Editor of MapBench.
Part of our map maker hub
Voronoi Map Generator sits in the map maker cluster, alongside 26 other tools that answer neighbouring questions with different methods or datasets.
You may also need
When this answer is only part of the job, these clusters cover the next step.
Read the guide behind this tool
Free Printable Blank Maps: How to Choose Outline, Labeled, or City Variants — Classroom worksheets, sales territories, and presentation slides need different map styles. How to pick blank vs labeled vs coloured — and SVG vs PNG.