Accessibility vs. Usability
Accessibility and usability are closely related - but not synonymous.
The difference is crucial for accessible and usable design.
Definitions
Accessibility bezeichnet die Zugänglichkeit eines Systems für Menschen mit Einschränkungen.
Usability beschreibt, wie effektiv, effizient und zufriedenstellend ein System genutzt werden kann – unabhängig von Einschränkungen.
Similarities
Both concepts are aimed at:
- a improved use of digital systems
- barrier reduction and needs-based design
- User-centeredness and Contextuality
- Normative foundation (e.g. WCAG & ISO 9241)
Take Home Message
Accessibility is a prerequisite - usability is the goal.
Focus on differences
| Aspect | Accessibility | Usability |
|---|---|---|
| Target group | People with disabilities (sight, hearing, motor skills, cognition) | All users |
| Goal | Enable access | Simplify use |
| Standards | WCAG, EN 301 549, BITV | ISO 9241-11, -110, -210 |
| Rating | Conformity testing (checklists, tools) | User-based tests (e.g. usability tests) |
| Mandatory | Often legally binding | Often “only” quality-related |
Example
A button with sufficient color contrast, keyboard operation and screen reader compatibility meets accessibility requirements.
If it is also clearly labeled, consistently positioned and easy to find, it contributes to usability.
Accessibility ≠ Only for People with Disabilities
Accessible design also helps:
- older people with failing eyesight
- Users with temporary restrictions (e.g. arm in plaster)
- People in contexts with poor lighting, noise or time pressure
Conclusion
Accessibility is a minimum requirement to ensure that systems are accessible to everyone - usability also strives for an optimal user experience.
Only those who integrate both aspects can create truly inclusive and usable solutions.
Merksatz
Accessibility is the key to the door - usability is the way through.
Last modified: 17 June 2025