c3 is a D3-based reusable chart library that lets developers embed configurable, interactive SVG charts into web applications by describing each chart as a configuration object instead of writing D3 code directly.

What it is

c3 is a JavaScript charting library built on top of D3.js and released under the MIT licence. It is published on npm as c3, served through jsDelivr, and documented at c3js.org. The repository's topics — chart, d3, data-visualization, graph, graphics, interactive-visualizations, svg — map its scope precisely: it renders interactive SVG charts in the browser. It has no server component, no database, and no declared runtime dependency other than D3.

The problem it solves is the repetition D3 imposes. D3 gives complete control over SVG, but every chart in an application means writing and maintaining the same scale, axis, and rendering logic again. c3 replaces that per-chart D3 code with a reusable, declarative configuration surface, so a chart becomes data plus options rather than a bespoke rendering routine. The project states its purpose as enabling deeper integration of charts into web applications, which is the difference between a chart that participates in application code and one bolted on at the edge.

Key capabilities

• Declarative chart configuration: a chart is defined as a configuration object over data, not as imperative D3 code.
• Interactive SVG output, per the svg and interactive-visualizations topics.
• Built on D3.js, with the dependency declared as ^5.0.0.
• Distributed as the npm package c3 and available through jsDelivr.
• Full API reference published at c3js.org/reference.html, alongside a Getting Started guide and an examples gallery.
• Bundled sample set under htdocs/samples, runnable locally with npm run serve-static.
• MIT licence, with CI on CircleCI and coverage reported through codecov.io.

Who uses it and how

• Web application developers who need charts embedded inside an existing front end rather than rendered separately.
• Teams already using D3 that want to stop rewriting axis, scale, and rendering logic for each chart.
• Projects in mixed library stacks: the README routes questions about the interplay between c3 and another library, with AngularJS named as the example, to the Google Group rather than the issue queue.
• Contributors working against a defined process — raise an issue first, then a PR, include test cases for new features, do not bump the version number, squash commits.
• Anyone debugging output, since the README warns that custom CSS can modify c3 output.

Getting started

Install the npm package c3, or load it from jsDelivr, and follow c3js.org/gettingstarted.html. The bundled samples can be run locally with npm run serve-static.

How it compares

The facts name one related tool: D3.js, on which c3 depends. c3 sits above D3 as a reusable chart layer, trading D3's unrestricted control over the DOM for a configuration API that removes per-chart boilerplate, with D3 remaining the rendering engine either way. No other charting library is named in this entry, so on that axis c3 stands alone in this registry.

When to use it — and when not to

There is almost nothing to operate: c3 is a client-side library with no database, storage, or mail server, so the deployment burden is limited to the browser and D3 compatibility. A project pinned to a D3 major newer than 5.x cannot share that dependency with c3, and anyone needing a framework-native component or server-side rendering should look elsewhere. Two facts temper expectations: the repository carries 771 open issues, and the README defers documentation to c3js.org, so the repository is not a self-contained reference.

$ npm run serve-static