22 Free Tools for Data Visualization and Analysis
A pioneer in Web-based data visualization, IBM's Many Eyes project combines graphical analysis with community, encouraging users to upload, share and discuss information. It's extremely easy to use and very well documented, including suggestions on when to use what kind of visual data representation. Many Eyes includes more than a dozen output options -- from charts, graphics and word clouds to treemaps, plots, network diagrams and some limited geographic maps.
You'll need a free account to upload and post data, although anyone can browse. Formatting is basic: For most visualizations, the data must be in a tab-separated text file with column headers in the first row.
It took me about three minutes to create a bar chart of top H-1B visa employers.
It took perhaps another minute to create a treemap of the same data.
What's cool: Visualization can't get much easier, and the results look considerably more sophisticated than you'd expect based on the minimal amount of effort needed to create them. Plus, the list of possible visualization types includes explanations of the types of data each one is best suited for.
Drawbacks: Both your visualizations and your data sets are public on the Many Eyes site and can be easily downloaded, shared, reposted and commented upon by others. This can be great for certain types of users -- especially government agencies, nonprofits, schools and other organizations that want to share visualizations on someone else's server budget -- but an obvious problem for others. (IBM does offer a contact form for businesses interested in hosting their own version of the software.) In addition, customization is limited, as is data file size (5MB).
Skill level: Beginner.
Runs on: Java and any modern Web browser that can display Flash.
You can see some featured visualizations on the Many Eyes home page or browse through some of the tens of thousands of uploads. One interesting map shows popular surnames in the U.S. from the 2000 Census by Martin Wattenberg, one of the creators of Many Eyes.
What it does: Although VIDI's website bills this as a tool for the Drupal content management system, graphics created by the site's visualization wizard can be used on any HTML page -- no Drupal required.
What's cool: This is about as easy as Many Eyes -- with more mapping options and no need to make your visualization and data set public on its website. There are quick screencasts explaining each visualization type and several different color customization options. And the file-size limit of 30MB is six times larger than Many Eyes' 5MB maximum.
Drawbacks: Oddly, the visualization wizard was a lot easier to use than the embed code -- my embedded iframe didn't display while trying to preview it on the VIDI website; I needed to save the visualization and go to the "My VIDI" page to get embed code that actually worked. Also, as with any cloud service, if you're using this for Web publishing, you'll want to feel confident that the host's servers can handle your traffic and will be available longer than your need to display the data.
Skill level: Beginner.
Runs on: Any Web browser.
Learn more: The VIDI home page features a link to an 11-minute video tutorial.
It took me less than five minutes to create a sample: a map of earthquakes of 7.0 magnitude or more since Jan. 1, 2000.
What it does: One of the more traditional corporate-focused business analytics offerings in this group, Zoho Reports can take data from various file formats or directly from a database and turn it into charts, tables and pivot tables -- formats familiar to most spreadsheet users.
What's cool: You can schedule data imports from sources on the Web. Data can be queried using SQL and can be turned into visualizations, and the service is set up for Web publishing and sharing (although if it's accessed by more than two users, you will need a paid account).
Drawbacks: Visualization options are fairly basic and limited. Interacting live with the Web-based data can be sluggish at times. Data files are limited to 10MB. I found the navigation confusing at times -- for example, after I saved a copy of a sample database, I was told it was in the folder "My reports," yet I had a hard time finding that.
Skill level: Advanced beginner.
Runs on: Any Web browser.
Code help: Wizards, libraries, APIs
Sometimes nothing can substitute for coding your own visualization -- especially if the look and feel you're after can't be achieved without an existing desktop or Web app. But that doesn't mean you need to start from scratch, thanks to a wide range of available libraries and APIs.
Choosel (under development)
What it does: This open-source Web-based framework is designed for charts, clouds, graphs, timelines and maps. Right now, it is geared more for developers who create applications than it is for end users who need to save and/or embed their work; but there's an interactive online demo that lets you quickly upload some data to visualize.
What's cool: As with Tableau Public, you can have more than one visualization on a page and connect them so that, for example, mousing over items on a chart will highlight corresponding items on a map.
Drawbacks: This is not yet an application that end users can use to store and share their work. And I found the online demo to be finicky about uploading data -- even after I corrected field formats for dates (dd/mm/yyyy) and location (latitude/longitude) as documented, my data wouldn't load until I had another text field added (rather than just having numerical fields). It was also unclear how to customize labels. This project shows promise if it's further developed and documented.
Skill level: Expert
Runs on: Chrome, Safari and Firefox.