What is Chartability?

Chartability is a set of heuristics (testable questions) for ensuring that data visualizations, systems, and interfaces are accessible. Chartability is organized into principles with testable criteria and focused on creating an outcome that is an inclusive data experience for people with disabilities.

What is Accessibility?

Accessibility (also sometimes abbreviated as a11y) is the practice of ensuring that as many people as possible can use, understand, and have access to a technology, infrastructure, tool, product, or service.

What is Data Visualization?

Data Visualization (also sometimes abbreviated as dataviz or datavis) is presenting data in a structured, symbolic way. The structure and semantics go beyond the visual, however, so we prefer to call these data experiences.

With the massive rise in data-driven journalism, the ease and availability of charting and analytical solutions, and data’s near-ubiquitous appearance in public life, more thorough and robust accessibility considerations are overdue.

Chartability's Principles

Chartability is organized into 7 principles, 4 common to the accessibility space: Perceivable, Operable, Understandable, and Robust (POUR) plus 3 more that extend from Robust: Compromising, Assistive, Flexible (CAF). These seven principles are used to focus explicitly on inclusive data experiences and the specific considerations produced by these challenging environments.

Why use Chartability?

Chartability is meant to be easy to get started, with a shortlist of 10 tests that can be conducted in 10-30 minutes (depending on the tester's experience), but also incredibly robust, with a full list of 45 tests across all 7 principles. To date, no Chartability audit has resulted in a full pass on the first try. It’s easy to get started yet encourages incredibly high standards.

What about Existing Standards?

Globally recognized accessibility standards (such as WCAG 2.1) and compliance requirements (such as the ADA and Section 508) are excellent and in no ways meant to be ignored or replaced by Chartability. But Chartability’s goals are not to help a data experience reach compliance or pass standards. The hope is, in fact, that Chartability can influence standards bodies like WAI, WCAG, and ARIA (and even eventually governance).

Is A11Y just Compliance?

Compliance is good in many ways, but it is also the ground of experience. The ceiling should be much, much higher. In fact, the ground of accessibility experience is often still significantly exclusive. In cases like interactive, dynamic, and challenging charts and graphs, compliance requirements are are still inaccessible to a wide array of people. These tools and experiences have become more and more common, which risks excluding more and more people.

No, A11Y includes Enjoyment

The United Nations’ Convention on the Rights of Persons with Disabilities (CRDP) in Article 10 (The Right to Life) states “every human being has the inherent right to life and [parties] shall take all necessary measures to ensure its effective enjoyment by persons with disabilities on an equal basis with others.”

Chartability seeks to affirm this human right and work towards making inclusion, accessibility, and enjoyment possible for charts, graphs, and data experiences.

Chartability goes Beyond

While Chartability includes many techniques and requirements straight from WCAG 2.1, it also goes beyond compliance requirements in many ways. Chartability can also be used in any context where data experiences can be found (not just on the web), making it useful to designers, engineers, developers, data analysts, scientists, product managers, and accessibility experts looking to gain special expertise.

Get the Workbook

Download Chartability’s workbook or read more about it at our POUR+CAF Github repo.

Get Help

While Chartability is very much the result of volunteer effort, there are services that we can provide related to data visualization and accessibility:

  • Training: Do you have a team and need some training?
  • Building: Are you looking to build inclusive data experiences and need specialized engineers and designers?
  • Auditing: Do you want confidence in knowing your team's charts and diagrams are accessible and want a professional external audit?

If you're interested in any of these services, feel free to reach out to us at:
or call +1-919-932-9872.

Learn More

Chartability comes with two primary resources for learning: you can download the powerpoint slide deck that goes along with an introductory, instructional video that you can watch here:

How to Stop Designing Inaccessible Data Visualizations from IRE/NICAR on Vimeo.

Talks, Workshops, and Podcasts with Chartability

[RECORDED] How to Integrate Accessibility into Your Data Viz Workflow (podcast), Frank Elavsky at Data Viz Today (May 2021)

[RECORDED] Accessibility in DataViz (podcast), Frank Elavsky at Tableau World Podcast (May 2021)

Entering Uncharted Territory: Accessible Data Visualization (talk/workshop), Frank Elavsky at Accessibility Camp Bay Area (May 2021)

Making Inclusive Charts (talk/workshop), Doug Schepers at AccessU (May 2021)

Accessibility is Critical to Data Visualization (talk/workshop), Frank Elavsky at NoVA UX (April 2021)

[RECORDED] How to Stop Designing Inaccessible Data Visualizations (talk/workshop), Frank Elavsky at IRE-NICAR (March 2021)

Introduction to Accessible Data Visualization (workshop), Frank Elavsky at Knowbility (December 2020)

Blogs, Articles, and Examples with Chartability

Vega-Lite Audit [alpha Chartability audit]

Chris DeMartini's Accessibility Journey [beta Chartability audit]

Example Chartability Audit [full beta Chartability audit]

(Project Coming Soon!)

Academic Papers Including Chartability

Cited by: A. Lundgard and A. Satyanarayan (2021) Accessible Visualization via Natural Language Descriptions: A Four-Level Model of Semantic Content. In IEEE VIS.

(In progress)

General A11Y + Data Visualization Resources

The group, DatavizA11y maintains an excellent resources shortlist as well as a larger list of resources, updated occasionally.

Support Us

With enough support we could develop improvements, training materials, tools, research, and more. There is already a lot of work being done in this space, but we could use some help.

Consider supporting Frank Elavsky’s Patreon, focused on data visualization and accessibility tools and research.

Want to get involved?

Nothing about us, without us! Chartability has been vetted and tested by an array of people with disabilities, including folks who are blind, low-vision, have motor impairments, cognitive impairments (ASD and AD/HD), and color vision deficiency. But even with all of that, it still could use more community contributors. The workbook’s online website is intended as the central source of collaboration and has a Github repo where community members are encouraged to open Issues for requests, feedback, and concerns. The goal is for Chartability to grow into a community-driven, community-centered piece of work.

Credits and Thanks

Chartability was created by Frank Elavsky and is licensed under the CC-BY-SA (Creative Commons Attribution-ShareAlike 3.0 Unported) license.

Chartability is generously sponsored by Fizz Studio as well as by supporters of Frank Elavsky’s Patreon.

This project was possible thanks to a broad collaboration with many people:

Doug Schepers of Fizz Studio for being a great partner, sponsor, and guide.

Early testers and folks who contributed feedback (in no particular order): Chris DeMartini, Emily Kund, Amber Thomas (The Pudding), Øystein Moseng (Accessibility at Highcharts), Jennifer Zhang and Ryan Shugart (Accessibility at Microsoft), Silvia Canelón and Liz Hare (MiR), Dominik Moritz (Vega-Lite), and many others who have requested that they remain anonymous.

Core members of the DatavizA11y group not already listed.