About GeoJason

GeoJason is a free suite of developer tools for working with GeoJSON, the open standard format for encoding geographic data structures defined in RFC 7946. The site is built for developers, GIS analysts, data scientists, and anyone who works with spatial data on the web.

Every tool runs entirely in your browser. Your data is never uploaded to a server, stored, or shared with third parties. There is no signup, no account, and no usage limits. You can process sensitive location data — customer addresses, proprietary boundaries, internal infrastructure maps — with confidence that nothing leaves your machine.

Why GeoJason Exists

Working with GeoJSON means constantly bouncing between tasks: checking if a file is valid, visualizing it on a map, converting formats for different tools, fixing coordinate order issues, and trimming file sizes. Most existing tools require accounts, upload your data to servers, or only handle one task at a time. GeoJason was built to handle all of these in one place with no friction and no privacy concerns.

The project started as a simple GeoJSON viewer and grew into a comprehensive toolkit after realizing how many common geospatial tasks share the same workflow: paste data, process it, see the result on a map, and copy the output. Every tool follows this pattern.

What You Can Do

GeoJason provides over 30 tools organized into three categories:

Tools — View GeoJSON on an interactive map, validate it against the RFC 7946 specification, simplify geometries to reduce file size, calculate areas, lengths, centroids, and bounding boxes, generate points and polygons, merge multiple files, create buffers, clip, union, intersect, dissolve, flatten multi-geometries, fix winding order, flip coordinates, and reduce coordinate precision.

Converters — Convert between GeoJSON and other common geospatial formats including KML (Google Earth), WKT (databases like PostGIS), GPX (GPS tracks), and latitude/longitude coordinate pairs.

Guides — In-depth developer guides covering the GeoJSON specification, best practices, coordinate reference systems, format comparisons, web mapping libraries, GeoJSON with PostGIS, Python integration, and JavaScript development.

Technology Stack

GeoJason is built with Next.js, a React framework that enables static site generation for fast page loads and strong SEO. The site is pre-rendered at build time so every page loads instantly without waiting for server-side rendering.

Spatial operations are powered by Turf.js, a modular JavaScript library for geospatial analysis. Turf handles everything from area and length calculations to buffer generation, simplification, and boolean operations like union and intersection. It runs entirely in the browser with no server dependency.

Maps are rendered with Leaflet, the most widely used open-source mapping library for the web. Map tiles come from OpenStreetMap, which provides free, community-maintained base maps. Format conversions for KML and GPX use the @tmcw/togeojson library, a well-maintained parser for XML-based geospatial formats.

Privacy and Data Handling

Data privacy is not a feature we added — it is how the site is architectured. There is no backend API that processes your data. There is no database that stores your files. The JavaScript that runs in your browser tab is the entire application. When you paste GeoJSON into a tool, it is parsed by your browser, processed by your browser, and displayed by your browser. Closing the tab deletes everything.

For full details, see our privacy policy and terms of service.

Contact

For bug reports, feature requests, or questions, email us at info@geojason.com.