WCAG 2.1 · Level A · Perceivable
WCAG 1.3.3 — Sensory Characteristics, explained with examples
Instructions must not rely solely on sensory characteristics like shape, color, size, position, or sound. "Click the green button" or "see the round icon to the right" excludes users who cannot perceive those characteristics.
- Number
- 1.3.3
- Level
- A
- Principle
- Perceivable
- Guideline
- 1.3 Adaptable
Why this criterion exists
"Click the green button" or "see the round icon to the right" excludes users who cannot perceive those characteristics.
If you only remember one thing: instructions must not rely solely on sensory characteristics like shape, color, size, position, or sound. Everything else on this page is detail.
Who feels it when this fails
Accessibility criteria sometimes feel abstract until you see who pays the cost when a site ignores them. Sensory Characteristics affects:
Color-blind users
Screen reader users
Users with low vision
How sites typically fail it
These are the patterns we see week after week. None are intentional — they are accidents of how teams build interfaces under deadline. Knowing the failure modes is the fastest path to writing them out of your component library.
"Click the red star" with no other identifier
"Use the icon at the top right"
How to test for it
Read instructions aloud; if they only make sense with sight, rewrite.
Automated scanners catch this criterion most of the time, but never all of the time. Manual testing with the keyboard and a screen reader closes the gap.
A code fix you can copy
Reference UI elements by name and role, not appearance.
The problem
<p>Click the round green button to continue.</p>The fix
<p>Click <strong>Continue</strong> to proceed.</p>Reference UI elements by name and role, not appearance.
Other Perceivable criteria
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