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.

Take Home Message

Accessibility is the key to the door - usability is the way through.

Frequently asked questions (FAQ)

What is the difference between accessibility and usability?

Accessibility means that digital content is accessible to people with disabilities. Usability describes how efficiently, effectively and satisfactorily a system can be operated by all users.

Why is accessibility not the same as usability?

Accessibility is a prerequisite for access, usability goes beyond that and optimizes the entire user experience - regardless of limitations.

What standards apply to accessibility and usability?

Accessibility is based on WCAG, EN 301 549 and BITV. Usability is based on ISO 9241-11, -110 and -210.

Does accessible design only help people with disabilities?

No. It also supports older people, people with temporary restrictions and anyone who works in difficult usage contexts (e.g. poor lighting, noise).

How do accessibility and usability complement each other in practice?

Accessibility opens the door by enabling access. Usability ensures that it is easy, efficient and pleasant to use.

Last modified: 2 November 2025