This is a practical guide to designing and implementing
accessible dashboards using R. Ensuring the accessibility of
dashboards benefits everyone. It not only allows people with diverse
abilities to access and interpret data, but also improves overall
usability.
This guide presents essential accessibility principles, offers
actionable design strategies and highlights common pitfalls to avoid. It
helps you build dashboards that are inclusive, user-friendly, and
impactful.
General Design Principles for Accessibility
Principles
-
Make content perceivable
- Use descriptive alt text for non-text content
- Avoid using only color to convey meaning
- Ensure sufficient contrast for text and UI elements
-
Make interactions operable
- Ensure all functions are keyboard-accessible
- Provide clear focus indicators
- Avoid time-limited interactions unless necessary
-
Make structure understandable
- Use consistent layout and predictable navigation
- Group related controls with landmarks (e.g.,
<main>
, <nav>
)
- Use headings (
<h1>
–<h6>
)
meaningfully and hierarchically
-
Make data accessible
- Provide downloadable raw data for visualizations
- Use accessible HTML tables to present data when possible
- Include text summaries of visualizations
-
Design for consistent behavior
- Reuse layouts and component patterns
- Ensure button/tab behaviors are predictable
- Avoid keyboard traps or focus loops
Dashboard Design Do’s & Don’ts
Include data tables with all
visualizations |
Show charts with no alternative format |
Use plain-language alt text and
summaries |
Hide alt text in tooltips or modals |
Limit interactions to key tasks |
Add hover-only or animated elements |
Highlight key insights and put less
important information to tooltips |
Use a large amount of text to fill the page and make
users dig through visual clutter |
Prioritize tables over interactive
visualizations or maps |
Assume all users can navigate interactive views |
Common Technical Pitfalls
1. Missing or Inadequate Alternative Text
<img> elements lack
alt , aria-label
|
Add alt or mark as decorative with
role="presentation"
|
SVGs with role="img" lack descriptive
labels |
Use <title> ,
aria-label , or aria-labelledby to describe the
icon’s purpose |
<iframe> lacks accessible name |
Add a descriptive title attribute or
aria-label
|
Buttons or links lack visible text or programmatically
associated label |
Add label via inner text, aria-label ,
aria-labelledby , or title
|
2. Insufficient Color Contrast
White text on a light background fails to meet the WCAG
AA contrast ratio requirement |
Ensure 4.5:1 contrast ratio for normal text (use WebAIM
Contrast Checker) |
3. ARIA Attribute Misuse
Invalid ARIA attributes for given role (e.g.,
aria-selected on <a> ) |
Use ARIA attributes only with compatible roles (e.g.,
aria-selected on role="tab" ) |
aria-label used with
role="presentation" or role="none"
|
Remove label or change the role to one that supports
labeling |
Misused or redundant roles on non-interactive
elements |
Use native HTML roles (like
<button> ) or remove unnecessary ARIA roles |
4. ARIA Role Structure & Hierarchy Errors
ARIA parent roles (e.g., grid ) lack
required child roles (e.g., row ) |
Follow correct structure:
grid → row → gridcell
|
ARIA child roles used out of context (e.g.,
gridcell not inside row ) |
Restructure DOM to enforce valid nesting |
Structural roles used without semantic purpose |
Use native HTML where possible for more predictable
accessibility |
5. Keyboard Navigation & Focus Management
Focusable elements lack accessible name (e.g.,
icon-only button) |
Add aria-label , title , or
text content that screen readers can access |
Scrollable containers not keyboard focusable |
Add tabindex="0" and ensure content is
reachable via keyboard |
Nested interactive controls (e.g., a
button inside a role="tab" container) |
Avoid interactive nesting; separate into distinct
controls |
Form inputs have hidden or missing labels |
Associate form fields with visible
<label> or use aria-labelledby or
aria-label
|
6. Structural & Semantic Violations
<a href="#"> or
<button> used without purpose or label |
Provide clear intent with text or ARIA attributes |
Mailto/email links not clearly labeled or visible |
Add contextual label (e.g.,
"Email us: example@email.com" ) with sufficient
contrast |
Iframes embedded without descriptive context |
Add title , wrap in
<section> , or provide heading to explain embedded
content |
Below are free, widely available tools you can use to evaluate the
accessibility of your dashboards:
-
axe DevTools Browser Extension:
Runs automated scans in your developer tools to flag WCAG issues and
suggest fixes right in the browser.
-
WAVE Browser
Extension: Adds an on‑page overlay that visually marks accessibility
errors, alerts, and structural cues for quick review.
-
WebAIM
Contrast Checker: Tests any foreground‑background color pair to
confirm it meets WCAG AA/AAA contrast ratios.
In addition to automated tools, always perform manual checks with a
screen reader. Popular options include VoiceOver
(macOS/iOS), NVDA (Windows), and JAWS
(Windows).