WCAG 1.3.3 Sensory Characteristics

Success Criterion 1.3.3 requires that instructions for understanding and operating content don't rely solely on sensory characteristics like shape, color, size, visual location, orientation, or sound. It's a Level A criterion under Guideline 1.3 (Adaptable).

The pattern this catches

Instructions like "click the round button," "see the box on the right," or "select the item below" all describe something purely in terms of a sensory characteristic — shape, position, sound. A blind user has no independent way to identify "the round button" among several buttons if roundness is the only distinguishing description given; someone using a screen magnifier who can only see part of the screen at once has no reliable sense of "the right" relative to a layout they can't view as a whole.

Common real examples

• "Press the green button to continue" (color as the only distinguishing feature)
• "Refer to the diagram above" (position as the only reference)
• "Swipe right to accept, left to decline" (direction/gesture as the only description, with no text-based fallback)
• "You'll hear a chime when it's ready" (sound as the only signal, with no visual or text equivalent)

The fix: pair sensory descriptions with a real identifier

The sensory description itself isn't forbidden — describing something as round or green is fine as a supplement. What's required is that there's always another way to identify the same thing that doesn't depend on perceiving that sensory characteristic: a label, a name, explicit text.

Before: "Click the round button to submit."
After: "Click the Submit button (round icon) to continue."

How this overlaps with, but differs from, color-only criteria

This criterion is closely related to 1.4.1 Use of Color, which specifically addresses color as an information carrier. 1.3.3 is broader — shape, size, position, and sound are all covered too, not just color — but the underlying principle is identical: don't make any single sensory channel the only way to identify or understand something.