Target size
Target size is the clickable / tappable area of an interactive element. WCAG 2.2 SC 2.5.8 (Target Size, Minimum) at Level AA requires every target to be at least 24×24 CSS pixels, with documented exceptions.
Detailed explanation
The 24×24 minimum applies to the clickable region, not the visible icon — a 16×16 icon inside a 24×24 padded button passes. Exceptions exist for inline targets in body text (a link inside a paragraph), targets with a 24×24 spacing buffer, user-agent defaults, and "essential" presentation (e.g., a map's native pin density).
This is the single most common WCAG 2.2 failure on mobile Shopify storefronts. Theme designers ship desktop-first 16×16 social icons or 18-line product variant pickers that fail on touch devices. Apple's Human Interface Guidelines recommend 44pt; Material Design recommends 48dp — both far above the 24-pixel WCAG minimum.
How this applies to Shopify stores
AccessComply's scanner measures every interactive element's computed bounding box at mobile viewport (375×667) and reports targets under 24×24. The fix agent adds padding via theme CSS to bring them to 24px without resizing the visual icon.
Primary source: w3.org