Geospatial Format Converter: Transform WKT, GeoJSON, GML, and TopoJSON

Are you working with spatial data across different platforms or applications? Our free, browser-based Geospatial Format Converter allows you to quickly and accurately convert between the most common geospatial data formats including WKT, GeoJSON, GML, and TopoJSON.

What is the Geospatial Format Converter?

The Geospatial Format Converter is a free, open-source tool designed to help GIS professionals, developers, data scientists, and mapping enthusiasts easily convert between different geospatial data formats. Whether you’re working with databases that use WKT (Well-Known Text), web applications that require GeoJSON, XML-based systems that use GML (Geography Markup Language), or data visualization tools that work with TopoJSON, this converter bridges the gap between these formats with just a few clicks.

Why You Need a Geospatial Format Converter

Different systems and applications often require specific geospatial data formats. For example:

• Database systems like PostgreSQL/PostGIS often use WKT for spatial data storage
• Web applications and modern APIs typically use GeoJSON for data exchange
• GIS systems may require GML for XML-based data interoperability
• Data visualization tools might work best with TopoJSON for efficient web mapping

Rather than writing custom code or using multiple specialized tools to convert between these formats, our converter provides a single, intuitive interface to handle all your conversion needs.

Key Features

• Interactive Map Drawing: Create geometries directly on the map using intuitive drawing tools
• Bidirectional Conversion: Convert from any supported format to any other format
• Format Validation: Automatic validation ensures your data is properly formatted
• Visual Verification: Instantly see your geometries rendered on an interactive map
• Copy to Clipboard: Easily copy converted data for use in other applications
• Example Data: Built-in examples for all geometry types and formats
• Mobile Friendly: Works on desktop, tablet, and mobile devices
• No Installation Required: Works entirely in your browser with no plugins or downloads

How to Use the Geospatial Format Converter

Basic Format Conversion

1. Select Input Format: Choose your source format (WKT, GeoJSON, GML, or TopoJSON)
2. Paste Your Data: Enter or paste your geospatial data in the input text area
3. Select Output Format: Choose your desired output format
4. Convert: Click the convert button to transform your data
5. Copy Results: Use the “Copy to Clipboard” button to copy the converted data

Interactive Map Features

The integrated map provides powerful visualization and editing capabilities:

1. Draw New Features: Use the drawing tools in the map’s top-right corner to create points, lines, polygons, and more
2. Edit Existing Features: Select and modify geometries directly on the map
3. Delete Features: Remove unwanted elements with the delete tool
4. Export Map Features: Convert map-drawn features to any supported format with one click
5. Import Data: Visualize existing data by converting it and clicking “Show on Map”

Quick Examples

Not sure where to start? Use the example buttons to load sample geometries for:

• Points
• LineStrings
• Polygons
• MultiPoints
• MultiLineStrings
• MultiPolygons
• GML structures
• TopoJSON structures

Supported Formats Explained

WKT (Well-Known Text)

WKT is a text-based representation of vector geometry used by many spatial databases, including PostGIS. It’s human-readable and represents geometries in a compact format like:

POINT (-73.9857 40.7484)

or

POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))

GeoJSON

GeoJSON is a JSON-based format for encoding geographic data structures. It’s widely used in web mapping and APIs because it’s lightweight and easy to parse in JavaScript:

{
  "type": "Feature",
  "geometry": {
    "type": "Point",
    "coordinates": [-73.9857, 40.7484]
  },
  "properties": {}
}

GML (Geography Markup Language)

GML is an XML-based format for geographic information developed by the Open Geospatial Consortium (OGC). It’s often used in enterprise GIS systems and for data interchange:

<gml:Point>
  <gml:pos>-73.9857 40.7484</gml:pos>
</gml:Point>

TopoJSON

TopoJSON is an extension of GeoJSON that encodes topology, making it more efficient for representing features that share boundaries. It’s ideal for web maps where file size matters:

{
  "type": "Topology",
  "objects": {
    "example": {
      "type": "GeometryCollection",
      "geometries": [{"type": "Point", "coordinates": [0, 0]}]
    }
  },
  "arcs": [],
  "transform": {
    "scale": [0.0000898311, 0.0000890715],
    "translate": [-73.9857, 40.7484]
  }
}

Common Use Cases

• Database Integration: Convert WKT from database queries to GeoJSON for web applications
• API Compatibility: Transform data between different APIs requiring different formats
• Data Visualization: Convert complex data formats to formats supported by visualization libraries
• Software Compatibility: Bridge the gap between different GIS software requirements
• Learning: Understand the structure of different geospatial data formats through conversion
• Quick Editing: Make simple edits to geospatial data without specialized GIS software
• Data Validation: Check if your geospatial data is properly formatted

Limitations and Considerations

While our converter is powerful, there are some limitations to be aware of:

• Complex Features: Very complex geometries with thousands of coordinates may experience performance issues in the browser
• Advanced Properties: Some format-specific advanced properties might not be preserved during conversion
• Coordinate Reference Systems: The converter assumes WGS 84 (EPSG:4326) coordinates and doesn’t transform between different coordinate systems
• 3D Geometries: Only 2D geometries are supported; Z-values (elevation) will be ignored during conversion
• Large Files: Files over several megabytes may cause browser performance issues
• TopoJSON Limitations: The simplified TopoJSON conversion doesn’t perform topological analysis for arc encoding

Whether you’re a GIS professional, web developer, or data scientist, our Geospatial Format Converter simplifies working with spatial data across different platforms and applications.

Frequently Asked Questions (FAQ)

General Questions

Q: Is this tool completely free to use?
A: Yes, the Geospatial Format Converter is completely free to use with no limitations or hidden costs.

Q: Do you store or collect my geospatial data?
A: No. All conversions happen in your browser, and no data is sent to any server. Your data remains private and secure.

Q: Do I need to create an account to use the converter?
A: No account is required. Simply visit the page and start converting your geospatial data.

Q: Does this tool work on mobile devices?
A: Yes, the converter is responsive and works on smartphones and tablets, though the experience is optimized for larger screens.

Format-Specific Questions

Q: What versions of GeoJSON are supported?
A: The converter supports GeoJSON according to the RFC 7946 specification, which is the current standard.

Q: Does the converter support all WKT geometry types?
A: The converter supports the most common WKT types including POINT, LINESTRING, POLYGON, MULTIPOINT, MULTILINESTRING, and MULTIPOLYGON. GEOMETRYCOLLECTION is not fully supported.

Q: Can I convert a full GML document with multiple features?
A: Yes, the converter can handle GML documents containing multiple features and will convert them to a FeatureCollection in GeoJSON.

Q: Does the TopoJSON conversion preserve topology?
A: The current implementation does a simplified conversion to TopoJSON without full topological analysis. It does not optimize arcs for shared boundaries.

Usage Questions

Q: How do I create a new geometry from scratch?
A: Use the drawing tools in the top-right corner of the map to create points, lines, or polygons directly on the map.

Q: How can I edit coordinates precisely?
A: You can manually edit the text representation in the input or output boxes, then click “Show on Map” to visualize your changes.

Q: Can I convert multiple geometries at once?
A: Yes, you can convert multiple geometries by using a GeoJSON FeatureCollection, a WKT collection, or by drawing multiple features on the map.

Q: How do I switch the conversion direction?
A: Double-click the convert button to change the direction of conversion (the arrow will reverse).

Troubleshooting

Q: Why does my WKT not display correctly on the map?
A: Ensure your WKT is properly formatted with the correct geometry type prefix (like “POINT” or “POLYGON”) and coordinate format. Also check that coordinates are in the expected longitude/latitude order.

Q: I’m getting a parsing error with my GeoJSON. What’s wrong?
A: GeoJSON requires properly formatted JSON. Common issues include missing commas, unquoted property names, or incorrect nesting of brackets. Try validating your JSON with a JSON validator first.

Q: The map is not loading. What should I do?
A: Ensure you have a stable internet connection, as map tiles require internet access. Try refreshing the page or using a different browser if issues persist.

Q: Why are my complex geometries slow to display?
A: Geometries with thousands of coordinates may cause performance issues in the browser. Consider simplifying very complex geometries before conversion.

Technical Questions

Q: What coordinate system does the converter use?
A: The converter and map use WGS 84 (EPSG:4326) coordinates, which is the standard for web mapping (longitude, latitude).

Q: Can I convert between different coordinate reference systems?
A: No, this tool does not perform coordinate system transformations. All data is assumed to be in WGS 84.

Q: Does the converter support 3D geometries?
A: No, the converter only supports 2D geometries. Any Z-values (elevation) in your data will be ignored during conversion.

Q: Is there a size limit for the data I can convert?
A: There’s no hard limit, but browser performance may degrade with very large datasets (multiple megabytes). For large data processing, consider using server-side tools like GDAL.

Q: Can I programmatically access this converter’s functionality?
A: The converter is designed for manual web use. For programmatic conversion, consider libraries like Turf.js, GDAL, or PostGIS, which offer similar functionality for different environments.

Q: What browsers are supported?
A: The converter works on all modern browsers including Chrome, Firefox, Safari, and Edge. Internet Explorer is not supported.