MobileTouchTarget44px [constraint] v1.0.0

Every touch-activated control must present a hit area of at least 44×44 CSS pixels on touch viewports. Visual rendering may be smaller, but the effective hit target (via padding or ::before expansion) must reach 44×44.

Target

• interactive elements on touch viewports
• buttons / links / form controls / icon buttons rendered ≤ 768px

Severity

high

Values

• • Minimum: 44 × 44 CSS px
  • Source: Apple HIG (iOS)
• • Minimum: 48 × 48 dp
  • Source: Material Design (Android)
• • Threshold: WCAG 2.2 SC 2.5.8 Target Size (Minimum)
  • Value: 24 × 24 CSS px
  • Level: AA
• • Threshold: WCAG 2.1 SC 2.5.5 Target Size (Enhanced)
  • Value: 44 × 44 CSS px
  • Level: AAA

Exceptions

• Inline links inside a paragraph (covered by surrounding line-height / read-mode).
• Decorative non-interactive elements.
• Adjacent identical controls in a paginated list (per WCAG SC 2.5.8 'inline' exception) where 24×24 is acceptable.
• Desktop / pointer-only viewports may relax to 32×32.

Approved Alternatives

• Visual icon at 24×24 with padding: 10px to reach 44×44 hit area.
• ::before { content: ''; position: absolute; inset: -10px } to expand hit area without changing visual size.
• Tailwind: p-2.5 on icon buttons; minimum h-11 w-11 (44px) on bare buttons.

Enforcement

Storybook a11y addon + axe-core target-size rule. Visual regression with min-touch-area overlay in dev mode.

MobileTouchTarget44px [constraint] v1.0.0

Every touch-activated control must present a hit area of at least 44×44 CSS pixels on touch viewports. Visual rendering may be smaller, but the effective hit target (via padding or ::before expansion) must reach 44×44.

Target

• interactive elements on touch viewports
• buttons / links / form controls / icon buttons rendered ≤ 768px

Severity

high

Values

• • Minimum: 44 × 44 CSS px
  • Source: Apple HIG (iOS)
• • Minimum: 48 × 48 dp
  • Source: Material Design (Android)
• • Threshold: WCAG 2.2 SC 2.5.8 Target Size (Minimum)
  • Value: 24 × 24 CSS px
  • Level: AA
• • Threshold: WCAG 2.1 SC 2.5.5 Target Size (Enhanced)
  • Value: 44 × 44 CSS px
  • Level: AAA

Exceptions

• Inline links inside a paragraph (covered by surrounding line-height / read-mode).
• Decorative non-interactive elements.
• Adjacent identical controls in a paginated list (per WCAG SC 2.5.8 'inline' exception) where 24×24 is acceptable.
• Desktop / pointer-only viewports may relax to 32×32.

Approved Alternatives

• Visual icon at 24×24 with padding: 10px to reach 44×44 hit area.
• ::before { content: ''; position: absolute; inset: -10px } to expand hit area without changing visual size.
• Tailwind: p-2.5 on icon buttons; minimum h-11 w-11 (44px) on bare buttons.

Enforcement

Storybook a11y addon + axe-core target-size rule. Visual regression with min-touch-area overlay in dev mode.

Rationale

Fitts's Law: smaller targets at greater distance from finger origin produce more mis-taps. Empirical Apple research found the average adult fingertip pad is 10–14mm, requiring ~44pt of touch surface to reliably target without parallax error. Sub-44 hit areas are the single most common cause of frustration in mobile UI tests.