Understanding Success Criterion 2.5.5: Target Size

Success Criterion 2.5.5 Target Size (Level AAA): The size of the target for pointer inputs is at least 44 by 44 CSS pixels except when:

The target is available through an equivalent link or control on the same page that is at least 44 by 44 CSS pixels;
The target is in a sentence or block of text;
User Agent Control
The size of the target is determined by the user agent and is not modified by the author;
A particular presentation of the target is essential to the information being conveyed.


The intent of this success criteria is to ensure that target sizes are large enough for users to easily activate them, even if the user is accessing content on a small handheld touch screen device, has limited dexterity, or has trouble activating small targets for other reasons. For instance, mice and similar pointing devices can be hard to use for these users, and a larger target will help them activate the target.

Touch is particularly problematic as it is an input mechanism with coarse precision. Users lack the same level of fine control when using inputs such as a mouse or stylus. A finger is larger than a mouse pointer, and generally obstructs the user's view of the precise location on the screen that is being touched/activated.

The issue can even be further complicated with responsive layouts on small screens like mobile, which need to accommodate different types of fine and coarse inputs. Both input types must be supported for a site that can be accessed both on a traditional desktop/laptop with a mouse, as well as on a tablet or mobile phone with a touch screen.

While this criterion defines a minimum target size, as a best practice it is recommended that larger sizes are used to reduce the possibility of unintentional activations. This is particularly relevant if any of the following are true:

The targets on a screen can have different purposes and uses, and this Success Criterion specifies how each is to be handled.

Equivalent targets: If there is more than one target on a screen that performs the same action, only one of the targets need to meet the target size of 44 by 44 CSS pixels.

Inline: Content displayed can often be reflowed based on the screen width available. This is known as responsive design and makes it easier to read since you do not need to scroll both horizontally and vertically. In reflowed content, the targets can appear anywhere on a line and can change position based on the width of the available screen. Since targets can appear anywhere on the line, the size cannot be larger than the available text and spacing between the sentences or paragraphs, otherwise the targets could overlap. It is for this reason targets which are contained within one or more sentences are excluded from the target size requirements.


If the target is the full sentence and the sentence is not in a block of text, then the target needs to be at least 44 by 44 CSS pixels.


A footnote or an icon within or at the end of a sentence is considered to be part of a sentence and therefore are excluded from the minimum target size.

User Agent Control: If the size of the target is not modified by the author through CSS or other size properties, then the target does not need to meet the target size of 44 by 44 CSS pixels.

Essential: If the target is required to be a particular target size and cannot be provided in another way, while changing it would essentially change the information or functionality of the content, then the target does not need to meet the target size of 44 by 44 CSS pixels.



Related Resources

Resources are for information purposes only, no endorsement implied.


Each numbered item in this section represents a technique or combination of techniques that the WCAG Working Group deems sufficient for meeting this Success Criterion. However, it is not necessary to use these particular techniques. For information on using other techniques, see Understanding Techniques for WCAG Success Criteria, particularly the "Other Techniques" section.

Sufficient Techniques

  • Ensuring that touch targets are at least 44 by 44 CSS pixels.
  • Providing a mechanism to change the size of the target independent of magnification.

Advisory Techniques

Although not required for conformance, the following additional techniques should be considered in order to make content more accessible. Not all techniques can be used or would be effective in all situations.

  • Ensuring inline links provide sufficiently large activation target.


The following are common mistakes that are considered failures of this Success Criterion by the WCAG Working Group.

  • Failure of success criterion 2.5.5 due to target size being less than 44 by 44 CSS pixels.
  • Failure of success criterion 2.5.5 due to target size of a paragraph that is also a link being less than 44 by 44 CSS pixels.

Key Terms

css pixel

visual angle of about 0.0213 degrees

A CSS pixel is the canonical unit of measure for all lengths and measurements in CSS. This unit is density-independent, and distinct from actual hardware pixels present in a display. User agents and operating systems should ensure that a CSS pixel is set as closely as possible to the CSS Values and Units Module Level 3 reference pixel [[!css3-values]], which takes into account the physical dimensions of the display and the assumed viewing distance (factors that cannot be determined by content authors).


if removed, would fundamentally change the information or functionality of the content, and information and functionality cannot be achieved in another way that would conform

pointer input

input from a device that can target a specific coordinate (or set of coordinates) on a screen, such as a mouse, pen, or touch contact


See the Pointer Events definition for "pointer" [[!pointerevents]].


region of the display that will accept a pointer action, such as the interactive area of a user interface component


If two or more targets are overlapping, the overlapping area should not be included in the measurement of the target size, except when the overlapping targets perform the same action or open the same page.