CesiumJS is an open source JavaScript library for world-class 3D mapping. With more than 500,000 downloads, CesiumJS powers apps that reach millions of users.

Learn more   Cesium on GitHub  



We don't just make our source code available; we set CesiumJS users up for success by supporting their work.


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The API documentation, tutorials, and Sandcastle code examples give developers everything they need to get started.



View featured CesiumJS applications that demonstrate a variety of use cases.

View showcases on our blog

Open standards & formats

When it comes to visualizing diverse geospatial data, in real time, Cesium is breaking new ground. We've adopted open formats wherever they were available, and we've developed open formats where they weren't, setting the standard for open 3D geospatial formats.

3D Tiles

A specification for streaming massive heterogeneous 3D geospatial datasets such as photogrammetry, CAD, and 3D building models.



The open standard 3D runtime format for 3D models. Developed with the Khronos Group.



A specification for efficient 3D terrain streaming and rendering.



The "Cesium Language", a JSON schema for describing time-dynamic 3D scenes.


Open source projects

To realize the full potential of 3D geospatial, we've also started and contributed to open source projects in the 3D ecosystem in addition to CesiumJS.

AnalyticalGraphicsInc / webglreport

A web page that reports a browser's WebGL capabilities.

AnalyticalGraphicsInc / 3d-tiles-tools

Tools for debugging, analyzing, and validating 3D Tiles tilesets that we developed with the University of Pennsylvania.

AnalyticalGraphicsInc / czml-writer

A C# and Java library for writing CZML content.

AnalyticalGraphicsInc / cesium-concierge

A GitHub bot for that automates common GitHub tasks such as welcoming first time contributors and reminding you to write tests.

glTF ecosystem

KhonosGroup / COLLADA2GLTF

A tool to convert COLLADA files to glTF that we contributed to, originally started by Motorola Mobility.

AnalyticalGraphicsInc / obj2gltf

A tool to convert OBJ assets to glTF that we developed.

AnalyticalGraphicsInc / gltf-pipeline

Content pipeline tools for optimizing glTF assets that we developed with the University of Pennsylvania.

AnalyticalGraphicsInc / gltf-vscode

An extension for Visual Studio Code that adds features for previewing and editing glTF files that we developed that Microsoft contributes to.

AnalyticalGraphicsInc / gltf-utilities

A JavaScript utility library that provides a consistent API for loading glTF resources from a remote URL that we developed.

AnalyticalGraphicsInc / wetzel

A documentation tool to generate Markdown documentation from JSON Schema we developed that Microsoft contributes to.

Community building


We write, edit, and review high quality content online and in print. Our blog is recognized as a go-to source of information about 3D geospatial. Our team has contributed to a number of books, including 3D Engine Design for Virtual Globes, WebGL Insights, and Real-Time Rendering, fourth edition.



We mentor students from University of Pennsylvania, Google Summer of Code, and the European Space Agency Summer of Code in Space. These students have produced significant open source projects in the Cesium, 3D Tiles, WebGL, and glTF communities.

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OSM sponsor

We are sponsors of OpenStreetMap, the largest user-generated map in the world. Many Cesium developers use OSM imagery in their applications. We're happy to support the OSM community and contribute to the sustainability of this open dataset.

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Our team members have served on committees for open source conferences such as FOSS4G NA and FeoGeoDay, and we regularly sponsor, attend, and present on Cesium, 3D graphics, and building open source communities at many conferences and universities.



We encourage adoption of open source and open standards by curating projects and bringing developers together. We're invested in supporting formats and tools around Cesium, 3D Tiles, and glTF that serve the entire community.

Our GitHub  

Help fund feature development

Contribute to the open-source community by funding feature requests to support your project. Let Cesium's experts do the heavy lifting in 3D visualization and analytics to accelerate your development cycle.

Contact our sales team.

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We welcome community contributions in all forms, code and beyond.

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