Understanding SC 2.1.4: Character Key Shortcuts (Level A)
In Brief
- Goal
- Reduce accidental activation of keyboard shortcuts.
- What to do
- Ensure character-only shortcut keys can be turned off or modified.
- Why it's important
- Character-key shortcuts are easy to accidentally trigger, especially with speech input.
Success Criterion (SC)
If a keyboard shortcut is implemented in content using only letter (including upper- and lower-case letters), punctuation, number, or symbol characters, then at least one of the following is true:
- Turn off
- A mechanism is available to turn the shortcut off;
- Remap
- A mechanism is available to remap the shortcut to include one or more non-printable keyboard keys (e.g., Ctrl, Alt);
- Active only on focus
- The keyboard shortcut for a user interface component is only active when that component has focus.
Intent
The intent of this Success Criterion is to reduce accidental activation of keyboard shortcuts. Character key shortcuts work well for many keyboard users. However, they can be inappropriate and frustrating for speech input users, whose dictation is interpreted as strings of letters, and for keyboard users who are prone to accidentally hit keys. To rectify this issue, authors need to allow users to turn off or reconfigure shortcuts that are made up of only character keys.
Note
Even though this Success Criterion refers to character keys
, note that it's not relevant whether a shortcut can be activated using a single physical key on a keyboard, or if it requires a combination of keys to be pressed. For instance, on most full-size US and UK keyboard, the ? (question mark) symbol is accessed using Shift+/ (forward slash key next to the right-hand Shift key). On a UK keyboard, in Windows, the é (lowercase "e" with an acute accent) requires the use of AltGr+e. The specific key combination required for certain characters will also vary depending on the user's keyboard layout. However, shortcuts that use these characters still fall under the requirements of this Success Criterion. What matters is that a shortcut relies on a printable character (letters, punctuation, numbers, symbol characters), and not the number of physical keyboard keys that users need to press to trigger it.
Note
The Success Criterion also applies to situations where a shortcut is based on a sequence of character keys – for example, pressing G and then A in quick succession to trigger an action. While the individual character key presses don't immediately trigger the action, overall these types of shortcuts still rely on a series of character keys.
This success criterion doesn't affect components such as listboxes and drop-down menus. Although these components contain values (words) that may be selected by one or more character keys, the shortcuts are only active when the components have focus. Other components such as menus may be accessed or opened with a single non-character shortcut (e.g., Alt or Alt+F) before pressing a single character key to select an item. This makes the full path to invoking a menu a two-step shortcut that includes a non-printable key. Accesskeys are also not affected because they are generally (depending on the user agent) activated using modifier keys.
Background on the mechanics of speech input
Speech input users generally work in a single mode where they can use a mix of dictation and speech commands. This works well because the user knows to pause before and after commands, and commands are usually at least two words long. So, for instance, a user might say a bit of dictation, such as "the small boat", then pause, and say a command to delete that dictation, such as "Delete Line". In contrast, if the user were to say the two phrases together without a pause, the whole phrase would come out as dictation (i.e., "the small boat delete line"). Although speech input programs often include modes that listen only for dictation or only for commands, most speech users use the all-encompassing mode all the time because it is a much more efficient workflow. It could decrease command efficiency significantly if users were to change to command mode and back before and after issuing each command.
Speech users can also speak most keyboard commands (e.g., "press Control Foxtrot") without any problems. If the website or app is keyboard enabled, the speech user can also write a native speech macro that calls the keyboard command, such as "This Print" to carry out Ctrl+P.
Single-key shortcuts are the exception. While using single letter keys as controls might be appropriate and efficient for many keyboard users, single-key shortcuts are disastrous for speech users. The reason for this is that when only a single key is used to trip a command, a spoken word can become a barrage of single-key commands if the cursor focus happens to be in the wrong place.
For example, a speech-input user named Kim has her cursor focus in the main window of a web mail application that uses common keyboard shortcuts to navigate (k), archive (y) and mute messages (m). A coworker named Mike enters her office and says "Hey Kim" and her microphone picks that up. The Y of "hey" archives the current message. K in "Kim" moves down one conversation and M mutes a message or thread. And, if Kim looks up and says "Hey Mike" without remembering to turn off the microphone, the same three things happen in a different sequence.
A user interacting with a webpage or web app that doesn't use single-character shortcuts doesn't have this problem. Inadvertent strings of characters from the speech application are not interpreted as shortcuts if a modifier key is required. A speech user filling in a text input form may find that a phrase that is accidentally picked up by the speech microphone results in stray text being entered into the field, but that is easily seen and undone. The Resources section of this page contains links to videos demonstrating these types of issues.
Benefits
- Speech users will be able to turn off single-key shortcuts so they can avoid accidentally firing batches of them at once. This will allow speech users to make full use of programs that offer single-key shortcuts to keyboard users.
- Keyboard-only users who have dexterity challenges can also be prone to accidentally hitting keys. Those users would be able to avoid problematic single character shortcuts by turning them off or modifying them to include at least one non-character key.
- Allowing all shortcut keys to be remapped can help users with some cognitive disabilities, since the same shortcuts can be assigned to perform the same actions across different applications.
Examples
Disable Shortcuts
A mechanism is provided to allow users to disable character-key shortcuts. The character key shortcuts are not the only way to carry out these commands. A speech user disables the shortcuts and can prevent words that are picked up by the microphone from triggering single-key shortcuts.
Alternate Control
Keyboard-only users are in a long issues thread. While reading the thread they accidentally hit the S key, which moves focus to the search bar at the top of the document. This causes them to lose their place and train of thought. However, a mechanism is provided to allow users to change character-key shortcuts. They change the shortcut to include another key so they can avoid future interruptions.
Related Resources
Resources are for information purposes only, no endorsement implied.
Web apps that use character-key shortcuts and allow users to disable and/or change these shortcuts:
- Gmail
- WordPress
Videos of speech user trouble with single character key shortcuts:
Techniques
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
Failures
The following are common mistakes that are considered failures of this Success Criterion by the WCAG Working Group.
Key Terms
- assistive technology
hardware and/or software that acts as a user agent, or along with a mainstream user agent, to provide functionality to meet the requirements of users with disabilities that go beyond those offered by mainstream user agents
Note
Functionality provided by assistive technology includes alternative presentations (e.g., as synthesized speech or magnified content), alternative input methods (e.g., voice), additional navigation or orientation mechanisms, and content transformations (e.g., to make tables more accessible).
Note
Assistive technologies often communicate data and messages with mainstream user agents by using and monitoring APIs.
Note
The distinction between mainstream user agents and assistive technologies is not absolute. Many mainstream user agents provide some features to assist individuals with disabilities. The basic difference is that mainstream user agents target broad and diverse audiences that usually include people with and without disabilities. Assistive technologies target narrowly defined populations of users with specific disabilities. The assistance provided by an assistive technology is more specific and appropriate to the needs of its target users. The mainstream user agent may provide important functionality to assistive technologies like retrieving Web content from program objects or parsing markup into identifiable bundles.
- conformance
satisfying all the requirements of a given standard, guideline or specification
- keyboard shortcut
alternative means of triggering an action by the pressing of one or more keys
- mechanism
process or technique for achieving a result
Note
The mechanism may be explicitly provided in the content, or may be relied upon to be provided by either the platform or by user agents, including assistive technologies.
Note
The mechanism needs to meet all success criteria for the conformance level claimed.
- process
series of user actions where each action is required in order to complete an activity
- relied upon
the content would not conform if that technology is turned off or is not supported
- technology
mechanism for encoding instructions to be rendered, played or executed by user agents
Note
As used in these guidelines "Web Technology" and the word "technology" (when used alone) both refer to Web Content Technologies.
Note
Web content technologies may include markup languages, data formats, or programming languages that authors may use alone or in combination to create end-user experiences that range from static Web pages to synchronized media presentations to dynamic Web applications.
- user agent
any software that retrieves and presents Web content for users
- user interface component
a part of the content that is perceived by users as a single control for a distinct function
Note
Multiple user interface components may be implemented as a single programmatic element. "Components" here is not tied to programming techniques, but rather to what the user perceives as separate controls.
Note
User interface components include form elements and links as well as components generated by scripts.
Note
What is meant by "component" or "user interface component" here is also sometimes called "user interface element".
Test Rules
The following are Test Rules for certain aspects of this Success Criterion. It is not necessary to use these particular Test Rules to check for conformance with WCAG, but they are defined and approved test methods. For information on using Test Rules, see Understanding Test Rules for WCAG Success Criteria.