Dashboard week | Day 2- Accessibility

by Anastasija Starkina
The purpose of visualization is insight, not picture.   Ben Schneiderman

Today our task was to produce a dashboard with universal design -ensuring that a wide number of people can use, understand, and have access to it. Below is the outcome of this day's challenge:

Link: Dashboard week day 2: FIX MY STREET | Tableau Public

In this blog post I will explain:

  1. How to make your dashboard more accessible?
  2. Why it is important?
  3. Accessibility dashboard design- bad practices
  4. Share useful links that could help you along the way

Tips to make dashboard more accessible?

Data visualization itself is a form of accessibility technology. It tries to spread the information to the wide number of people and as such, requires to take into consideration a wide range of factors. Below is the list of features you can add to your dashboard to make it more universal:

  1. Use color-blind accessible palette
  2. Labeling line directly ( in high- contrast color)
  3. Making text and mark size larger
  4. Avoiding visual overloading with marks, colors, or categories.
  5. Using captions to describe the chart. Makes it available for screen readers.
  6. Showing most recent value (keyboard controllers cannot access tooltips).
  7. Outlining how to interact with chart and see underlying values.
  8. Using no more than 10 colors or shapes.
  9. Including clear, explicit instructions for how to use the dashboard (don’t just rely on symbols).
  10. Using newer versions of Tableau make it easy to include a button to download the data as a crosstab which can be opened in Excel.
  11. Using Alt text on images and button.
  12. Using titles whenever possible; These are read aloud by screen readers along with specific text describing how to operate with keyboard.
  13. Giving titles to legends.
  14. Using contrast 4.5:1 for normal text and 3:1 for large text.

Why it is important?


● 18% of working age population of Britain have a disability (as defined by Equality Act of 2010)

● Competitive advantage if we're the best when it comes to universal design.

● Many companies have policies around accessibility.


● Being a strong and vocal advocate or universal design can get your work noticed and encourage other companies to follow suit.

● Users of products that are particularly good/accessible are often vocal advocates with their community.


● Some clients have legal requirements to make accommodations for users of assistive devices.


● Living with a disability makes life harder in many ways, we should avoid making even tougher where we can.

Adapted from Kyle Waterworth, Alteryx Accessibility project manager

Bad visualization practices:

● Mark selection and actions are not supported for keyboard navigation.

● Tooltips are also not supported for keyboard navigation- Alternative is to direct users to “View underlying data” where the tooltip information will appear ctrl+shift+enteraccesses “View underlying data” table on web.

● Views with over 1000 marks are not WCAG conformant because they are rendered by the server and not the browser.

● Views that use the polygon mark type are always rendered by the server.

Useful resources

NVDA- Takes information from the Document Object Model (DOM) and verbalizes it for the user.

Funkifychrome extension-Simulates a variety of impairments (e.g. low vision, tremor, colourblindness) in browser setting.

Color Palette contrast checker-Compass up to 5 different colors for contrast accessibility and suggests replacements

Color Oracle -Color blindness simulator.

Edit XML for Focus Order Walkthrough-Kelly Gupton, Director of Project Management, Tableau

Tableau Accessibility FAQ

TC19: Designing Accessible Dashboards in Tableau-Kelly Gupton

Chartability–Rubric for scoring “Data Experiences” on accessibility

Follow #a11y on twitter


Anastasija Starkina

Thu 30 Sep 2021

Mon 27 Sep 2021

Sun 01 Aug 2021