An interactive data visualization tool. VizWit uses a JSON config file to generate interactive charts that cross-filter one another. It currently supports data hosted in Socrata and Carto, which includes open data provided by cities such as Philadelphia, Chicago, and San Francisco). Data that’s hosted elsewhere can be supported by adding a new data provider.





VizWit cards are configured via JSON objects. The layout is defined using size and order properties on those objects, generated by the Config Builder (work in progress). The resulting JSON file is then hosted on, a free and easy service to share code snippets. The Gist ID is then used in the VizWit URL (ie. This allows viewers to fork the Gist and build their own VizWit page.

Configuration Documentation

Build your own

Visit the builder (work in progress) and add a few cards, then configure them using the wrench icon. When you’re finished, click Export and copy the configuration code into a new “gist” at Once you click Create, you should see your new “gist” and the “gist id” of random characters in the URL (ie. 813483da72ac781f8b13). Use that gist id to go to

Alternatively, use the live editor to edit the raw JSON alongside a live representation of it.

If you’d like to share what you’ve created, post an issue with a link to it.


VizWit is a client-side JavaScript application. The application is structured using Backbone. Charts are built using AmCharts. Maps are built using Leaflet. Tables are built using DataTables. Tests (of which there are not nearly enough!) are run using Mocha. The interactive layout is generated by Gridstack. The application is compiled using Browserify. See the full list of dependencies in package.json

How it works

vizwit.js is the primary chart-generating module. It takes a container selector and a config object and uses them to initialize a view (bar chart, map, table, etc.). The views are passed a collection and a filteredCollection, which are identical and allow the view to query the data provider (Socrata). Views generate the chart/map/table/etc. and listen for user interactions on them. On an interaction, the view triggers the global event object with the filter (ie. state=PA), and all views that use the same dataset receive the event and use their filteredCollection to query the data provider with the filter passed through the event. By using a separate collection, VizWit can show the “filtered value” and the “original value” side-by-side.

The actual entry point is either vizwit-loader.js or vizwit-embed.js. vizwit-loader.js fetches a gist or local file, reads its configuration, and passes it to layout.js to create a layout on the page. Then for each chart in the configuration, layout.js calls init() from vizwit.js as described above. vizwit-embed.js simply finds the parent container of the <script> tag that was embedded, and calls init() from vizwit.js inside of it. This way of embedding allows the VizWit library to only be loaded once on the page with as many charts embedded in any element (example).



GPL-2 (create an issue if that doesn’t work for someone)