Want to make an online map? There are plenty of free tools to choose from. Some of the options include:
- GeoCommons [no longer available]
- Google Fusion Tables
- Google's My Maps
- GPS Visualizer
The best choice for you depends on factors such as what kind of data you have (spreadsheet or shapefile; points or lines; etc.), what kind of functionality you would like in the final map, and what your technical comfort is with things like HTML or CartoCSS. That said:
- If you are looking to easily map a point dataset with just addresses and/or latitude or longitude coordinates, we recommend BatchGeo or GPS Visualizer.
- If you want more customization of symbols and infowindows and already have lat-long coordinates, try CartoDB.
- If you want lots of customization and have time to learn or already know CartoCSS (custom cartography using cascading style sheets), you may want to look into using Mapbox with TileMill.
Comparison of Six Online Mapping Tools
In an effort to help with making that decision two of the library's GIS staff members, Rebecca and Joël, did a methodological comparison of six free online mapping tools with a point dataset in February 2014. They compared BatchGeo, CartoDB, GeoCommons, MangoMap, Mapbox, and WorldMap (links go to maps made during comparison). For the free version of each tool they looked at:
- import file types
- in-tool geocoding (getting latitude-longitude coordinates for addresses)
- basemap options
- ease of updating the data once it was uploaded in the tool
- symbology options
- info windows
- time series capabilities
- map publishing options
- export file types
The spreadsheet with all the details can be found on Google Drive, which is the best way to find out if a particular tool meets your specifications. There are summarizing images and descriptions below for input and output file types, geocoding, and information window and symbology customization.
Input and Output File Types
Between the six free online mapping tools, there are 15 different input filetypes (CSV and KML are most common) and 12 different output filetypes (KML is the most common). Overall, if the data to be mapped is in a spreadsheet (XLS or CSV) then it is in good shape to be uploaded. WorldMap is the only tool that requires data to be uploaded in shapefile format.
For output file types if you want to export the data, all but MangoMap export in Google Earth (KML) format. MangoMap doesn't provide a data export option. All of the tools provide stable links to the final map produced and all but GeoCommons provide an embed code.
Several of the tools offer in-tool geocoding, which enables users to have a list of cities, street addresses, or latitude-longitude coordinates and the tool will place the points in the correct location. BatchGeo and GeoCommons are the only ones that can geocode lat-long, city name, and street address, and CartoDB and MangoMap can only geocode with lat-long coordinates. Neither Mapbox nor WorldMap can geocode at all.
Customizing Symbology and Info Windows
There is a wide variety of customization capabilities. When it comes to symbology, all but BatchGeo and GeoCommons permitted customizing the colour of the point symbols, and four of the six tools provide options for graduated and choropleth symbols as well as opacity adjustments. For info windows (the boxes that appear when a point is clicked), all but Mapbox permitted live links from the data table, and four of the tools allow for embedding images in the info window from a link in the data table.