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TOPOJSON Converter
TOPOJSON files usually open only in GIS software. reaConverter reads them directly and converts whole folders into formats colleagues and clients can use.
How to Convert .topojson Files in Bulk
1. Install reaConverter
2. Select TOPOJSON Files
3. Start Conversion
Step by step
See It in Action
For quick and effortless TOPOJSON file handling on your PC, reaConverter offers powerful conversion tools with batch processing. Best of all, it works entirely offline — ensuring your sensitive data never leaves your computer.
GIS Toolkit
Do more with your GIS data
Need TOPOJSON data in someone else's software? reaConverter moves layers between GIS, CAD and document formats without QGIS or ArcGIS, and works through whole folders in one pass.
- Move layers between GIS formats such as Shapefile, GeoJSON, KML, KMZ and GPX
- Bring map data into CAD as DXF or DWG, and turn CAD drawings into Shapefiles
- Render maps to PDF, SVG, PNG or JPG for reports, slides and print
- Convert incoming survey and field data automatically with Watch Folders
- Script GIS conversions from the command line for pipelines and scheduled jobs
- Keep cadastral, utility and client data on your PC: nothing is uploaded
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Average User Rating:Last updated on July 28, 2026
Questions & Answers
TOPOJSON files: Frequently Asked Questions
What are TOPOJSON files?
TOPOJSON is a map file in JSON text form that describes shapes as chains of shared line pieces, called arcs, instead of repeating the coordinates for every shape. A file contains a single object of type Topology, which has an arcs member with a list of all the arcs, an objects member with the named layers of the map, and optionally a transform member. Each shape in an object does not hold coordinates but a list of arc numbers, so two neighboring regions that share a border both point to the same arc, and an arc that has to be walked backwards is marked by a negative number. The coordinates inside the arcs can be reduced in size in two ways. They are rounded to whole numbers on a grid, and the transform member gives the scale and the shift that turn these numbers back into real coordinates, and each position is stored as the difference from the previous one, which makes the numbers small. The geometry types are the same as in GeoJSON: Point, MultiPoint, LineString, MultiLineString, Polygon, MultiPolygon, and GeometryCollection. Attributes are attached to the shapes, as in GeoJSON. To use the data in a program that expects ordinary shapes, the arcs have to be joined back into complete lines and polygons.
Can reaConverter open TOPOJSON files?
reaConverter fully supports the TOPOJSON file format – open, edit, and export TOPOJSON files to any other popular file format with ease.
Do I need QGIS or ArcGIS to convert TOPOJSON files?
No. reaConverter reads TOPOJSON files on its own, so the conversion needs no GIS installation and no licence. It handles whole folders at once, which suits survey archives, tile sets and data deliveries that have to reach people working in other software.
How do I change TOPOJSON to another format?
reaConverter is a user-friendly tool for converting TOPOJSON files. Once installed on your computer, it allows you to convert all your .topojson files at once with just a few clicks. You can even convert topojson images directly from Windows Explorer using the right-click menu — fast and convenient.
Why choose offline conversion with reaConverter?
Keep your sensitive data 100% private with offline processing that never exposes files to cloud risks. Our software meets strict compliance standards (GDPR, HIPAA, CCPA) while handling confidential documents for legal, healthcare and financial sectors.
Can I convert TOPOJSON online?
If you only want to convert a few TOPOJSON files, you are welcome to try our free online TOPOJSON converter.
How can I turn TOPOJSON files on my computer to another format?
The best way to convert TOPOJSON files on your PC is to get a quality piece of software, such as reaConverter. This software is extremely efficient in managing a wide range of batch files conversions, including conversion from TOPOJSON.
How can I automate TOPOJSON files conversion?
reaConverter supports all the essential automation features, such as right-click сonversion and Watch Folders, for the most efficient automated file conversion in any software of its kind.
Can I convert TOPOJSON files using scripts or the command-line interface?
reaConverter provides full access to all its features from the Windows command-line shell, including the command-line topojson converter.
What else can I do with reaConverter?
Change format settingsCopy metadata (EXIF, IPTC)Convert GIS filesConvert Gerber filesChange color space
What formats can I convert a TOPOJSON file to?
Discover More
Beyond TOPOJSON conversion
Convert .topojson files in batches of any size, with editing and processing applied along the way. The same tool also handles 800+ other formats, including CAD, medical imaging, and GIS.
