GIS Tools - Hex Grid & Fishnet Grid Generator

What Is a Hex Grid Generator?

A hex grid generator creates a tessellation of hexagonal cells over a specified geographic extent. Hex grids are also called hex bins, hexagonal tessellations, or hexagonal fishnets. Each cell is a regular hexagon with equal side lengths and six vertices, tiled to cover the extent without gaps or overlap. Hex grids have become one of the most popular analytical grids in GIS because of their uniform neighbor distance, rotational symmetry, and visually smoother output compared to square grids. If you need to produce a hex grid GIS layer for binning point data, aggregating counts, running zonal statistics, or building an analytical dashboard, a hex grid generator is the starting point.

The Hex Grid & Fishnet Grid Generator on gis.tools produces either hexagonal or square (rectangular fishnet) grids from any extent, directly in your browser. Drop in a bounding polygon or specify a bounding box manually, set the cell size, pick hex or square, and download the result as a GeoJSON, KML, or Shapefile. The tool supports the classic "flat-top" and "pointy-top" hex orientations and can also produce grids aligned to H3 hex grid resolution levels.

Hexagonal grid GIS workflows are used in crime mapping, wildlife surveys, retail analytics, transportation demand, and any time a regular tessellation is required for binning, aggregation, or visualization.

How Hex Grids Are Generated

A hexagonal grid is defined by:

An origin point (the center of the reference cell)
The cell size (width or circumradius)
Orientation (flat-top or pointy-top)
The extent to cover

The generator walks through the extent in a double-offset coordinate system (or axial coordinates), emitting one hex polygon per cell. Each cell is assigned a unique ID that can be used as a join key for binning downstream.

H3 Hex Grid Integration

H3 is Uber's open-source discrete global grid system that indexes the Earth's surface into hexagonal cells at 16 resolution levels, from roughly 4 million km² per cell (resolution 0) down to 0.9 m² per cell (resolution 15). Each H3 cell has a unique 64-bit index that encodes both location and resolution. The gis.tools hex grid generator can output cells aligned to H3 boundaries, letting you integrate with Uber Kepler.gl, H3-aware databases, and other H3 ecosystem tools.

Square Fishnet Grids

The same tool can generate square cells (rectangular fishnets) when you need a grid aligned to existing rasters or CAD datums. Square grids are simpler to compute and easier to relate to raster cell boundaries.

Key Parameters and Options

Cell Shape

Hexagon or square.

Cell Size

For hexagons: the circumradius (distance from center to vertex) in meters or CRS units. For squares: the edge length.

Orientation

Flat-top or pointy-top for hexagons. Flat-top is more common in American analytics; pointy-top is the default for H3.

Bounding Extent

Auto-detect from a loaded layer, or specify a bounding box manually with min/max longitude and latitude, or drop in a polygon to clip the grid to.

H3 Resolution

Optional H3 resolution level (0-15) to generate cells aligned to Uber's H3 index.

Practical Applications

Point Binning and Hotspot Mapping

Bin points into hex cells to produce density maps. See the Density Grid tool for a dedicated binning workflow.

Uniform Sample Grid Generation

Create a uniform grid of sample points (as hex centers) for fieldwork planning, where each cell represents a single sampling unit.

Thematic Mapping

Aggregate demographic, economic, or environmental attributes into hex cells for thematic mapping that avoids the visual noise of irregular administrative boundaries.

Machine Learning Feature Engineering

Hex grids are a standard feature-engineering approach for geospatial ML: convert continuous coordinates into discrete cell IDs, compute per-cell aggregates, and use those as model inputs.

Dashboards and Tiled Maps

Hex grids at fine H3 resolutions power high-performance aggregation dashboards in tools like Deck.gl and Kepler.gl.

Urban Planning

Planners aggregate zoning, parcels, or infrastructure attributes into hex cells to compare neighborhoods on a common tessellation.

Wildlife and Ecology

Hex grids are preferred for wildlife sampling because the uniform neighbor distance reduces shape-induced bias in occupancy models.

Telecommunications

Cellular network planners use hex grids (matching the geometric intuition of cell coverage areas) for capacity planning.

Step-by-Step Workflow in gis.tools

Open the Hex Grid & Fishnet Grid Generator
Either drag in a layer (the tool will use its extent) or enter a bounding box manually
Choose hex or square cells
Set the cell size in meters or CRS units
Optionally select an H3 resolution for H3-aligned cells
Click "Generate Grid"
Preview the grid on the map
Export as GeoJSON, KML, or Shapefile

Worked Example

A retail analyst wants to produce a 1-kilometer hex grid across a metropolitan area to aggregate store sales data. She drops the metro boundary polygon into the tool, selects hexagons with a 1 km circumradius, and clicks Generate. The output is 1,482 hex cells covering the metro, each with a unique ID. She then uses the Spatial Join tool to count store sales within each cell and styles the result with the Graduated Styling tool to produce a sales-density dashboard.

Common Pitfalls and Gotchas

CRS matters: hex grids generated in WGS84 degrees will be distorted and non-square in shape. Reproject to a metric CRS first.
Cell size units: if your CRS is in degrees, a "100" cell size is 100 degrees, not 100 meters. Check the units.
Very small cell sizes over large extents produce millions of cells and can exhaust browser memory.
Alignment drift: cells don't necessarily align to round coordinate boundaries unless you set the origin explicitly.
H3 orientation: H3 cells are pointy-top; choosing flat-top breaks H3 alignment.
Edge cells may extend beyond the bounding polygon and need to be clipped afterwards.
Grid-aware joins: if you need to join hex cells across projects, the cells must be generated with the same origin and size.
Projection-specific "hex" look: a true regular hex only appears regular in its source CRS.

Tips for Best Results

Reproject to a metric CRS (UTM, Web Mercator, Albers Equal Area) before generating
Use H3 alignment if you plan to share cells across projects
Clip to a meaningful boundary (metro, state, park) with the GIS Clip Tool (Clip Layer by Polygon) to remove irrelevant cells
Assign each cell a stable ID for downstream joins
Pair with Spatial Join to aggregate attributes into the grid

Comparison with Other GIS Approaches

QGIS provides Create Grid under Vector > Research Tools. ArcGIS Pro has Generate Tessellation in Data Management with H3 support since version 3.1. PostGIS has ST_Hexagon and ST_Square. Turf.js has turf.hexGrid and turf.squareGrid. H3 is available as bindings in many languages. The browser-based gis.tools generator is the fastest path from an extent to a downloadable grid for quick analytical projects.

Performance Considerations

Generating the grid is O(c) where c is the number of cells. Millions of cells can be generated in seconds but may be too large to render or export efficiently. Pick a cell size appropriate to your use case.

Data Privacy and Browser-Based Processing

Generating a grid from a confidential project extent (e.g., a mining claim or a private estate) stays in your browser. No coordinates are uploaded.

Related GIS Concepts

H3 is Uber's hierarchical hex grid system with 16 resolution levels. S2 is Google's competing hierarchical grid using spherical squares. Geohash is another global grid system using rectangular cells. Fishnet is the traditional GIS term for a square grid. MAUP (Modifiable Areal Unit Problem) is the well-known issue that aggregation grid choice affects results.

Frequently Asked Questions

How do I generate a hex grid for GIS?

Drop in an extent or bounding polygon, pick hexagons, set cell size, and click Generate.

Is this an H3 hex grid generator?

Yes — optionally align cells to H3 resolution levels so they match Uber's H3 index.

What's the difference between hex and square grids?

Hex cells have uniform neighbor distances and look smoother; squares are easier to compute and align to rasters.

How do I bin points into the hex grid?

Use the Spatial Join tool or the Density Grid tool to count points per cell.

Can I use this grid with Kepler.gl?

Yes — if you generate with H3 alignment, the output cells have H3 indexes matching Kepler's expectations.

About Grid Types