Understanding Success Criterion 2.1.1: Keyboard

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.

This exception relates to the underlying function, not the input technique. For example, if using handwriting to enter text, the input technique (handwriting) requires path-dependent input but the underlying function (text input) does not.

This does not forbid and should not discourage providing mouse input or other input methods in addition to keyboard operation.

Intent of Success Criterion 2.1.1: Keyboard

The intent of this Success Criterion is to ensure that, wherever possible, content can be operated through a keyboard or keyboard interface (so an alternate keyboard can be used). When content can be operated through a keyboard or alternate keyboard, it is operable by people with no vision (who cannot use devices such as mice that require eye-hand coordination) as well as by people who must use alternate keyboards or input devices that act as keyboard emulators. Keyboard emulators include speech input software, sip-and-puff software, on-screen keyboards, scanning software and a variety of assistive technologies and alternate keyboards. Individuals with low vision also may have trouble tracking a pointer and find the use of software much easier (or only possible) if they can control it from the keyboard.

Examples of "specific timings for individual keystrokes" include situations where a user would be required to repeat or execute multiple keystrokes within a short period of time or where a key must be held down for an extended period before the keystroke is registered.

The phrase "except where the underlying function requires input that depends on the path of the user's movement and not just the endpoints" is included to separate those things that cannot reasonably be controlled from a keyboard.

Most actions carried out by a pointing device can also be done from the keyboard (for example, clicking, selecting, moving, sizing). However, there is a small class of input that is done with a pointing device that cannot be done from the keyboard in any known fashion without requiring an inordinate number of keystrokes. Free hand drawing, watercolor painting, and flying a helicopter through an obstacle course are all examples of functions that require path dependent input. Drawing straight lines, regular geometric shapes, re-sizing windows and dragging objects to a location (when the path to that location is not relevant) do not require path dependent input.

The use of MouseKeys would not satisfy this Success Criterion because it is not a keyboard equivalent to the application; it is a mouse equivalent (i.e., it looks like a mouse to the application).

It is assumed that the design of user input features takes into account that operating system keyboard accessibility features may be in use. For example, modifier key locking may be turned on. Content continues to function in such an environment, not sending events that would collide with the modifier key lock to produce unexpected results.

Benefits of Success Criterion 2.1.1: Keyboard

Examples of Success Criterion 2.1.1: Keyboard

Resources Success Criterion 2.1.1: Keyboard

Techniques for Success Criterion 2.1.1: Keyboard

Sufficient Techniques

  1. Ensuring keyboard control for all functionality
  2. Ensuring keyboard control by using one of the following techniques.

  3. Providing keyboard-controllable event handlers using one of the following techniques:

  4. Preventing a keyboard trap in Flash content AND using the following techniques as applicable:

Advisory Techniques

  • Using XHTML role, state, and value attributes if repurposing static elements as interactive user interface components (future link) AND Adding keyboard-accessible actions to static HTML elements
  • Providing keyboard shortcuts to important links and form controls (future link)
  • Using unique letter combinations to begin each item of a list (future link)
  • Choosing the most abstract event handler (future link) (Scripting)
  • Using the onactivate event (future link) (Scripting)
  • Avoiding use of common user-agent keyboard commands for other purposes (future link)