Accessibility is the foundation of inclusion. It’s what ensures that everyone, regardless of ability, context, or device, can participate. It’s not just compliance; it’s clarity. An accessible design removes barriers before they appear, helping people focus on what they came to do, not how to get there.
Accessible design makes products usable by more people in more situations. It builds trust through respect and reduces frustration by anticipating needs. When accessibility is embedded from the start, usability improves for everyone.
This page shows how to evaluate accessibility, measure it with UX metrics, and turn principles into proof.
How to Use This Page
Use the Accessibility Heuristics to evaluate how well your product supports diverse abilities and contexts.
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Select a core page, flow, or task.
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Review each heuristic below with supporting UX metrics.
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Observe where users face barriers (visual, motor, auditory, or cognitive).
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Collect data through testing, assistive tools, or accessibility audits.
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Prioritize improvements where usability or comprehension break down.
Where This Fits in Glare
Accessibility belongs to the Define phase of Glare. It ensures foundational usability, before measuring delight or adoption. Accessible designs raise comprehension, confidence, and completion rates by making the interface perceivable, operable, understandable, and robust for all users.
Strong accessibility sets the tone for product maturity. It prevents rework, strengthens trust, and ensures every user can contribute to business outcomes.
Why Accessible Experiences Matter
Accessible design:
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Expands your audience by including more users.
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Reduces friction and support needs.
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Builds equity and trust through inclusion.
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Increases usability and satisfaction for everyone.
When designs respect differences, everyone benefits.
Common UX Metrics for Accessible Experiences
Behavioral Metrics (User Actions)
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Completion Rate — Measures how successfully users finish tasks across input methods or assistive tools.
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Comprehension — Evaluates how clearly users understand content or instructions.
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Effort — Captures how much correction, zooming, or repetition users need to succeed.
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Error Rate — Tracks how often users encounter accessibility-related issues (like focus loss or unclear labels).
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Satisfaction — Reflects how supported and in control users feel while using the product.
Accessibility Heuristics
Accessibility Heuristics translate inclusive design principles into everyday design habits.
Together, they make products perceivable, operable, understandable, and robust, so users of all abilities can navigate, act, and succeed without barriers. An accessible system doesn’t just comply with standards; it communicates clearly, works predictably, and earns trust through usability that includes everyone.
1. Perceivable Content
Everyone should be able to perceive what’s on screen. Information can’t rely on one sense alone. Text alternatives, contrast, and clear structure make content visible, audible, and readable.
Tips:
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Provide alt text for all non-text content.
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Maintain strong contrast ratios.
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Use semantic headings to support screen readers.
**Example:
**An ecommerce product photo includes alt text describing color and features, making it usable for screen reader users.
Metrics:
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Comprehension — Do users understand content through multiple modes?
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Error Rate — Are users missing key details due to visual barriers?
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Satisfaction — Do users describe the interface as readable and inclusive?
2. Operable Controls
All actions should be easy to trigger using different input methods.
Users must be able to navigate with a keyboard, mouse, touch, or assistive device.
Tips:
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Ensure all interactive elements are reachable via keyboard.
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Provide visible focus indicators.
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Avoid time-based interactions that penalize slower responses.
**Example:
**A web app allows complete navigation with tab keys, showing a visible highlight on active elements.
Metrics:
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Completion Rate — Can users complete tasks with varied input methods?
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Effort — How much repetition or rework is needed to operate controls?
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Task Success — Are expected actions reliably triggered?
3. Understandable Language
Users should easily grasp meaning and purpose.
Clear language, logical flow, and error prevention reduce confusion and support cognitive accessibility.
Tips:
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Use plain language and consistent terms.
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Provide clear error messages that explain fixes.
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Structure instructions in short, scannable steps.
**Example:
**A financial app replaces “authentication failure” with “We couldn’t verify your login—try again or reset your password.”
Metrics:
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Comprehension — Do users understand instructions without rereading?
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Error Rate — Are users making preventable mistakes?
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Satisfaction — Do users feel supported and informed?
4. Consistent Feedback
Feedback should confirm user actions clearly and in multiple forms.
Visual, auditory, or haptic responses help everyone know when an action succeeds or fails.
Tips:
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Provide confirmation through color and text, not color alone.
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Use ARIA live regions for dynamic updates.
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Offer non-visual cues for critical alerts.
**Example:
**A form submission shows both a green checkmark and the text “Form sent successfully.”
Metrics:
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Success Rate — Do users recognize when actions complete?
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Reaction — Do users describe feedback as helpful or confusing?
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Effort — How often do users need to repeat actions for confirmation?
5. Flexible Presentation
Content should adapt without breaking.
Zoom, orientation changes, or device differences shouldn’t disrupt usability.
Tips:
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Support text resizing up to 200%.
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Use responsive layouts that preserve structure.
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Ensure no content overlaps or disappears when scaled.
**Example:
**A mobile site adjusts text and layout fluidly when users zoom in, keeping labels readable.
Metrics:
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Task Success — Do users maintain functionality after adjusting view?
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Completion Time — How long does it take to complete tasks at different scales?
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Satisfaction — Do users feel the layout adjusts naturally?
6. Forgiving Recovery
Errors should be easy to fix without penalty.
Accessible systems help users recover smoothly after mistakes.
Tips:
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Keep user input persistent after refresh or error.
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Highlight fields with clear descriptions of what went wrong.
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Offer undo options and confirmation steps.
**Example:
**A signup form retains entered information after an error, showing which field needs attention.
Metrics:
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Error Recovery Rate — Can users fix issues without starting over?
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Completion Rate — Do they finish tasks successfully after correction?
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Sentiment — Do they feel supported through the process?
7. Compatibility with Assistive Tools
Designs should work with screen readers, voice commands, and other assistive technologies.
Tips:
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Test with NVDA, VoiceOver, and JAWS.
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Include ARIA roles and labels.
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Ensure dynamic elements announce changes properly.
**Example:
**A dashboard announces live updates like “New message received” through a screen reader.
Metrics:
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Success Rate — Do assistive tools read and operate all content?
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Usability — Are users completing tasks using assistive devices?
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Comprehension — Do users understand updates and alerts correctly?
Summary Insight
Accessible design expands what’s possible. When every user can perceive, operate, and understand your product, you build trust and widen reach.
Accessibility isn’t a checkbox—it’s a signal of respect. Strong accessibility means fewer barriers, faster progress, and higher satisfaction for everyone.
What to Do Next
Run an accessibility review on your most-used page or flow.
Observe users with varied devices and assistive tools. Track comprehension, completion, and effort.
Then move to the next Glare facet, Measure, to validate whether what’s accessible also performs as expected.
Resources
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Jakob Nielsen’s 10 Usability Heuristics for User Interface Design — NN/g
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Usability 101: Introduction to Usability — NN/g
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Top 10 Application-Design Mistakes — NN/g
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How to Conduct Usability Testing — Baymard Institute
