CSV → Hexagon Map

1. Upload a CSV file with latitude/longitude coordinates

2. Filter and preview your data

3. Select an area of the map for your hexagons

4. Generate hexagons with customizable sizes

5. Download results as GeoJSON files

Done! 🎉

This tool was originally developed at DW's Data Team for visuaizing FIRMS data on custom Datawrapper maps.

It was built with lots of help from LLMs and the open source power of Siimple, Turf.js, Leaflet, D3, H3, and Coloris.

This was an experiment at vibe coding and all the recklessness that it entails – always check if your data is sound.

Upload your CSV

Files must have a latitude and longitude column

Maximum 100MB or 500,000 rows

📁

Drop your file here

or click to browse

Or try with sample data (not updated – just for testing)

Filter the data

Expand any column to access its filter options. You can filter by categories (select specific values), numbers (set min/max ranges), or dates (choose start/end dates).

Active Filters

If you are working with fire maps from VIIRS (one of the satellites at FIRMS), remember to filter out low confidence entries in the confidence column!

No filters applied

Select area

Choose the geographic area for your hexagon map.

Points outside of this area will be excluded from the map.

Draw a rectangle

Click the drawing tools on the map to create a rectangle

Upload your GeoJSON

Or select an area from the list

Choose Resolution and Bin Size

Select the size of your hexagons and preview the results

Select resolution

This will control the size of your hexagons. 0 = largest, 15 = smallest

2 (123,930 km²)
Level 0: Continental (4.3M km²)
Level 3: Country (123,930 km²)
Level 6: City (36 km²)
Level 9: Neighborhood (0.7 km²)

Configure binning

Define how many bins you want to create and how many points per bin

Preview Map

See your hexagons before downloading

The map will have the following bins

You can change the color legend in the next step

Data Distribution

Visualize how your data is distributed across hexagons. If the two histograms have very different shapes, consider playing around with the size and number of the bins.

How many hexagons have exactly X points?

How many hexagons are in each bin?

Downlod & customize legend

Your hexagon map is ready! You can also customize an HTML color legend to use in Datawrapper

Preview map

Your processed hexagon map ready for download

Customize color legend

You can change the colors and then copy the HTML legend to use in your Datawrapper map

Hexagons generated: 0
File size: 0 KB

Single file

Download all hexagons in one GeoJSON file –– good for making custom Datawrapper choropleth maps

Multiple files

Download separate files for each bin category –– good for making Datawrapper locator maps