OPEN BETA

Build maps
in your browser

No installation required. A free, open Web GIS tool that supports GeoJSON, KML, CSV, and Shapefile for effortless map creation, editing, and conversion.

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Map editor screenshot
FEATURES

Everything you need to create maps, right in your browser

No software to install. Open your browser and start using professional GIS editing tools immediately.

Intuitive Drawing Tools

Create points, lines, polygons, rectangles, and circles with click & drag. Full vertex editing, property editing, and undo/redo support.

Table & Bulk Editing

View and edit all features in a table layout. Multi-select for bulk attribute updates, combine, and split operations.

Multi-Format Support

Import GeoJSON, KML, GPX, CSV, and TopoJSON. Export to GeoJSON, KML, CSV, TopoJSON, and Shapefile.

Address & Place Search

Integrated with the Geospatial Information Authority of Japan (GSI) API. Search results can be added directly as features on the map.

Measurement Tools

Measure distance, area, and coordinates with a click. Copy results instantly and paste them straight into your reports.

Auto-Save & Restore

Your map data is automatically saved to IndexedDB. Close the browser and come back later — your work is right where you left it.

FORMATS

Works with the formats you already use

Broad support for popular GIS file formats. Use WeMAPI as a simple format converter, too.

Import Export
GeoJSON GeoJSON KML KML GPX CSV / TSV CSV TopoJSON TopoJSON Shapefile
USE CASES

How people use WeMAPI

1

Field Location Logging

Drop points on survey sites, add addresses and notes as properties. Export to CSV and attach to your report.

2

Format Conversion

Convert KML files from partners to GeoJSON, or turn CSV coordinate data into Shapefiles in seconds.

3

Route & Area Sharing

Draw delivery routes or target areas as polygons. Share the URL to show team members the map instantly.

4

Learning GIS

Understand GeoJSON structure without installing anything. Inspect and edit raw data directly in the built-in code editor.

FAQ

Frequently Asked Questions

What is WeMAPI?

WeMAPI is a free, browser-based Web GIS tool that requires no installation or sign-up. You can create, edit, and convert geospatial data in formats like GeoJSON, KML, CSV, and Shapefile. All data is saved locally in your browser's IndexedDB — nothing is uploaded to any server.

What file formats does WeMAPI support?

Import: GeoJSON, KML, GPX, CSV/TSV, TopoJSON. Export: GeoJSON, KML, CSV, TopoJSON, Shapefile. CSV import supports Shift-JIS encoding, automatic header detection, and manual coordinate column selection.

Is WeMAPI free?

Yes, WeMAPI is completely free with no account required. Development is ongoing.

Can I convert KML to GeoJSON?

Yes. Import a KML file (via file picker or drag & drop), then select GeoJSON from the export menu. You can also convert between any supported formats — CSV to Shapefile, GPX to KML, and more.

Where is my data stored?

The map data you create is saved locally in your browser's IndexedDB and is never uploaded to a server. Your work is automatically restored when you revisit the page. (Separately, we use Google Analytics for anonymous traffic analysis.)

Map-making, simplified

No sign-up required. Completely free. Just open your browser and start creating.

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