2. Operable
2.1 Keyboard Accessible (Level A)
Contents
Guideline 2.1 Keyboard Accessible
User interface components and navigation must be operable.
Why must web pages be accessible without a mouse?
Some people cannot use or have difficulties using a mouse. For example:
- The mouse is designed to be guided by eye. Users who are totally blind cannot see the mouse pointer.
- Mouse pointers tend to be small. Individuals with low vision may have trouble spotting the mouse pointer on the screen.
- Someone with a learning disability may find the movements of the mouse pointer distracting, or they may lack the hand-eye coordination needed to reliably use a mouse.
- Some people have trouble remembering when to left-click, double-click, or right-click.
- A person who has hand tremors may be unable to hold the mouse steadily enough to click small screen objects. Some seniors who do not have hand tremors report difficulties holding the mouse steady enough to double-click.
Success Criterion 2.1.1 Keyboard
Level A
All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying function requires input that depends on the path of the user’s movement and not just the endpoints.
Keyboard Explained
The computer mouse is ubiquitous today, but before 1984 most computer users did not use one. The mouse only became pervasive during the mid–1990s. In recent years, other mouse-like devices have been introduced, including trackballs, touchpads, and trackpoints. Now, a mouse (or a similar pointing device) comes with every computer, and most people would be lost without one.
Yet some people cannot use — or have difficulties using — a mouse. For example:
- An individual with low-vision may have trouble locating the mouse pointer on a screen
- A person who is totally blind cannot see the mouse pointer at all
- Someone with a learning disability may find the movements of the mouse pointer distracting
- A person who has hand tremors may be unable to hold the mouse steadily enough to click on small screen objects
In addition, there are individuals who find that pressing a few keys on the keyboard is faster, easier, and more accurate than pointing and clicking. Many “average” computer users know a few keyboard shortcuts, and some “power users” rarely touch the mouse at all.
Many tasks that are typically done with a mouse can be (or should be) easily keyboard accessible, including “clicking” hypertext links, drawing straight lines and regular geometric shapes, and resizing windows. There are even keyboard equivalents for dragging and dropping. But when a task cannot be performed without a mouse, some people will be prevented from taking full advantage of a site.
WCAG 2.1 acknowledges that some tasks cannot reasonably be done with a keyboard, such as real-time flight simulations. Tasks that depend on continuous, time-sensitive movements that do not have start and end points are exclu