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CityJSON

For all CityJSON matters. Managed by @tudelft3d

CityJSON

Open encodings and tools for 3D city models

Website · Specifications · Software · Datasets


CityJSON is a JSON-based encoding of the CityGML data model, an OGC Community Standard for storing and exchanging 3D city models: buildings, roads, vegetation and terrain, with their semantics. This organisation hosts the specification and a family of formats and tools built around it, from a streaming variant to cloud-native encodings that are queried in place over HTTP.

The format family

CityJSON FlatCityBuf CityParquet
CityJSON and CityJSONSeq: the JSON encoding of CityGML, and its line-delimited streaming form. FlatCityBuf: a cloud-optimised binary encoding in FlatBuffers, with spatial and attribute indices for HTTP range requests. CityParquet: a columnar encoding in Parquet, queryable where it lies on object storage with no server.

Representative repositories

Specifications

  • specs: the CityJSON specification
  • extensions: the registry of CityJSON Extensions
  • stac-city3d: STAC extension for 3D city models

Formats

  • flatcitybuf: FlatCityBuf, with readers in Rust, C++, Python and TypeScript
  • cityparquet: the CityParquet specification and its Rust reference implementation
  • cjseq: create, process and convert CityJSONSeq

Tools

  • cjio: Python CLI to process and manipulate CityJSON files
  • cjval: the official validator for CityJSON and CityJSONSeq
  • convert: convert between CityJSON, CityJSONSeq, FlatCityBuf, CityParquet and OBJ, in the browser
  • cjdb: load CityJSON into PostgreSQL

Viewers and plugins

DuckDB extensions (experimental)

  • duckdb-cityjson: read and write CityJSON, CityJSONSeq, FlatCityBuf and CityParquet in SQL
  • duckdb-3d: 3D solid processing in SQL

Discovery

Pinned Loading

  1. specs specs Public

    Specifications for CityJSON, a JSON-based encoding for 3D city models

    Bikeshed 126 28

  2. cjio cjio Public

    CityJSON/io: Python CLI to process and manipulate CityJSON files

    Python 151 35

  3. cityjson-qgis-plugin cityjson-qgis-plugin Public

    A QGIS plugin that adds support for CityJSON files

    Python 49 15

  4. ninja ninja Public

    A web viewer for CityJSON files

    Vue 57 18

  5. cityjson-threejs-loader cityjson-threejs-loader Public

    JavaScript 30 22

  6. cjval cjval Public

    Official validator for CityJSON + CityJSONSeq datasets

    Rust 10 3

Repositories

Showing 10 of 38 repositories
  • duckdb-cityjson Public

    (Experimental) DuckDB extension for CityJSON

    cityjson/duckdb-cityjson's past year of commit activity
    C++ 11 MIT 1 1 1 Updated Oct 16, 2026
  • cityparquet Public

    A columnar encoding of CityJSON/CityGML

    cityjson/cityparquet's past year of commit activity
    Rust 4 Apache-2.0 1 0 2 Updated Oct 16, 2026
  • duckdb-3d Public

    (Experimental) DuckDB extension to process 3D geomerty

    cityjson/duckdb-3d's past year of commit activity
    C++ 4 MIT 0 1 1 Updated Oct 16, 2026
  • flatcitybuf Public

    CityJSON encoding with FlatBuffers

    cityjson/flatcitybuf's past year of commit activity
    Rust 33 3 1 3 Updated Oct 16, 2026
  • city3d-stac-tool Public

    A tool to generate STAC catalog, collection and item for 3D city models

    cityjson/city3d-stac-tool's past year of commit activity
    Rust 3 MIT 1 2 5 Updated Oct 14, 2026
  • convert Public

    Simple converter from any CityJSON invariants data formats to others

    cityjson/convert's past year of commit activity
    TypeScript 2 MIT 0 0 0 Updated Oct 12, 2026
  • cjseq Public

    Create+process+modify+convert CityJSONSeq

    cityjson/cjseq's past year of commit activity
    Rust 14 MIT 2 0 1 Updated Oct 12, 2026
  • .github Public
    cityjson/.github's past year of commit activity
    0 0 0 0 Updated Oct 12, 2026
  • city3d-stac-registry Public

    A registry for City3D STAC catalog

    cityjson/city3d-stac-registry's past year of commit activity
    Shell 6 MIT 1 0 3 Updated Oct 5, 2026
  • stac-city3d Public

    STAC extension for 3D city models

    cityjson/stac-city3d's past year of commit activity
    7 Apache-2.0 2 1 0 Updated Oct 5, 2026