Target Size Explained
This success criterion was added in WCAG 2.1 to ensure that people are able to activate actions either with a mouse click or a touch. Some people may have difficulty targeting small objects with a mouse pointer, perhaps having difficulty holding the mouse pointer steady enough to click a tiny target area.
One common way to make tiny web elements, such as radio buttons or checkboxes, targetable, is to label them with the HTML label element. When it is used the label itself becomes clickable, creating a larger target area to activate these tiny form elements.
Where target sizes often become problematic is in responsive designs. When web content is viewed on larger screens, target areas may meet the 44 by 44 pixel minimum dimensions, though when viewed on a small device, content may reflow and elements may be reduced in size to fit in the smaller space available. On mobile devices, targets need to be (a) large enough to be touchable with a finger tip without activating other nearby elements unintentionally, and (b) large enough so a finger tip does not completely obscure the element.
- Targets within a sentence
- When target size is essential and would invalidate an activity or function otherwise
- When an equivalent 44 by 44 target is provided, the original does not need to meet this requirement
- Links at the end of a sentence to a footnote (these are considered to be part of the sentence)
- Elements that are part of the operating system user interface or a user agent (e.g., browser)
Concurrent Input Mechanisms Explained
This success criterion was added in WCAG 2.1 to ensure that users are not limited in the input method they use to access web content. For a mobile device, a finger tip is typically the main input method. For a person who may have limited use of their fingers, however, they might choose to attach a mouse and keyboard to their device to make it easier to operate. Web content must not prevent the use of these or other alternate input devices.