Choropleth.net is a simple web app designed for quick visualization of geographic data on an interactive Leaflet.js map. Check out the Github Repository to see the source code and download test files to play with.
Create an account to start making maps. Once you are logged in, go to your "My Maps" page to create your first map.
Choropleth.net currently has the ability to parse any standard-delimited text files (.csv, .tab, etc.) and .xls(x) files. The file should have headers in the first row and data beneath. To help guide the parser, it is advised to use column names representing the type of geography you wish to map. The supported geography types and formats are:
* If mapping counties or cities formatted as names, a column including the containing state must also be included.
** If mapping census tracts formatted as names, a column including the containing state and county must also be included.
State, County, Pop. Density (Pop./mi2)
New York, New York, 46961
New York, Kings, 25848
New York, Bronx, 24118
Once your file is parsed, you will be brought to the editor page for your new map. The icon bar on the left shows the aspects of the map you are able to edit. The different editor sections are described in detail below.
The column names of the parsed file will henceforth be called "properties", and the rows containing data about a certain geography will be referred to as "features". Each feature is described by its properties.
Begin by giving your map a unique title, description, and any tags to index your map in searches (unavailable as of 11/21/20). The title will be displayed above the map, and if you add a description or tags they will be displayed when hovering over the info button on the upper left side of the map. There is also a link to a full-screen map that can be embedded in your own HTML.
This section of the editor shows a list of all of the properties from the uploaded file. The properties can be rearranged by dragging them up or down, hidden by unchecking them, or given aliases to use within the map interface. You can also specify the type of data the property describes, which will affect how each data point is displayed in the data box seen when hovering over features on the map.
Users can filter features on the map to display only those which meet certain property criteria by clicking the filter icon on the toolbar in the upper right corner of the map, and selecting filter options. When your file was uploaded, any column that contained numerical data, or categorical data with fewer than 10 unique entries, was determined eligible as a filter. All filters are enabled by default, but they can be added or removed in this page of the editor. The options for the filters are determined automatically, but support for custom options will be available in a future update.
Users can color features by their value for a certain property, either in a sequential fashion for numerical data, or simply by their categorical values. One property can be used as a choropleth at a time, and users can select from active choropleths by clicking the paint bucket icon on the toolbar in the top right corner of the map. Similar to filters, any file column that contained numerical data, or categorical data with fewer than 10 unique entries, was determined eligible as a choropleth, and every eligible choropleth is active by default. This section of the editor is used to change the color scheme of each choropleth, and to add or remove a user's ability to color the map by a certain property.
Users can search for property values by clicking the search icon on the toolbar and typing a query. The search field page of the editor is used to add or remove properties from the search index.
Change the map background, display/hide automatic geography labels, and set the boundary for the map on this editor page. To set the boundary, clear the current bondary, and move the map to the new desired boundary, then click "Capture current view."