• Success Criterion 2.5.1
  • Conformance level A

Two-Finger Gesture Required With No Single-Pointer Option

2.5.1 — Pointer Gestures

Scenario

Setting

A pharmacy app's prescription-refill form

What’s wrong

Two-finger pan/rotate requirements without single-pointer controls.

Example 

label.addEventListener('gesturechange', (e) => {
  label.style.transform = `rotate(${e.rotation}deg) scale(${e.scale})`;
});
// rotation and zoom are only reachable through a two-finger gesture

Why it matters

A patient confirming their prescription can't straighten a sideways label photo unless two fingers can touch the screen at once.

How to test

Try the two-finger pan/rotate action with a single finger or a button instead: if no single-pointer alternative exists, it fails.

How to fix

Any rotate-and-scale gesture needs single-tap buttons that perform the same rotation and zoom steps.

<button aria-label="Rotate label 90 degrees" onclick="rotateLabel(90)">⟳</button>
<button aria-label="Zoom in on label" onclick="zoomLabel(1.2)">+</button>

Outcome

A patient taps rotate twice, reads the label right-side up, and confirms the correct refill.

Who is affected

People who can only use one finger or a stylus, and users with a paralyzed or missing hand.

Learn more

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