Functional Accessibility
While most websites are built around the conventional use of computer mouse and keyboard, many people use alternative methods of navigating and interacting online—whether by keyboard, voice command, or switch device. Building a website that only supports traditional methods of input and navigation limits a significant group of people from interacting with your content and business.
What is functional accessibility
Defined simply, functional accessibility refers to whether or not a website can be operated by people with a wide range of physical and motor abilities. Functional accessibility is less about what a user perceives or understands, and more about how effectively they can operate it—through actions like clicking, scrolling, typing, submitting forms, and navigating.
Aspects of functional and visual accessibility can overlap, especially in regards to screen reader users. Where the barriers to visual accessibility relate more to the display and perception of information, barriers to functional accessibility relate to the interactions a user is able to perform.
Who is affected by functional accessibility
Motor and mobility disabilities
Any conditions that affect the hands, arms, or fine motor control can impact a user’s ability to use traditional mouse and touch interactions on their devices. Conditions such as paralysis, cerebral palsy, muscular dystrophy, limb differences, and more may render someone unable to use a mouse, limit their range of motion, or cause fatigue from repetitive input. While there are many alternate navigation methods, common solutions include using keyboards, mouth sticks, head pointers, eye tracking, voice control, and switch devices.
Tremors and reduced precision
Conditions like Parkinson’s disease, multiple sclerosis, and essential tremors can affect the steadiness and precision of movement, even if an individual’s broader mobility remains unaffected. In these instances specific pain-points like small targets, hover-dependent menus, and drag interactions can pose significant barriers to use.
In these instances, users may have hand function and even use a computer mouse—however, they’re more likely to rely on a keyboard as a primary or secondary source of navigation if there ability to precisely control a mouse is unreliable or if there symptoms fluctuate.
Repetitive strain and chronic pain
Common medical conditions like carpal tunnel syndrome, tendonitis, and chronic pain may limit how long or intensively someone is able to use a mouse or keyboard. These individuals may find themselves switching between input methods depending on the day or task. For these conditions, the efficiency of a website may significantly impact them; unnecessary steps, redundant interactions, and slow response times can make their experience more difficult or painful.
Temporary and situational motor limitations
Many people, at some point in their lives, will experience a condition that creates a short-term accessibility challenge. Broken arms, hand injuries, and surgeries can all make a standard mouse difficult or impossible to use during recovery. It’s often not until someone experiences this that they realize just how inaccessible the digital world is.
Even more common are every-day situations like a parent using a device while holding their child, or a person trying to multi-task while on a crowded train car—in both examples, the user is likely to experience limitations in their range of hand and arm movements. These are situational constraints that limit a users available input methods and may cause them to rely on voice or keyboard navigation. While these scenarios are not likely to be included in disability statistics, they are common and can create the same barriers within a website’s experience.
Types of alternate navigation devices
Switch devices
These are physical pieces of hardware—typically with one or two physical buttons or “switches”—that allow users to scan through and make selections on a website. Switch devices often align to the experience of using the “tab” and “enter” keys while navigating with a keyboard. Similar to keyboard navigation, switch devices require that a user to be able to access all interactions without a mouse.
Eye-tracking software
This technology leverages a camera to track a user’s gaze and map it to a position onscreen—making adequately sized targets essential. While new advancements in technology are beginning to introduce capabilities like “dwell” which allows users to simulate hover effects, these modes are often optional and able to be turned on or off depending on a user’s preference. In order to properly support eye tracking experiences (and touch-focused mobile experiences in general) you should avoid any hover-only interactions.
Sip and puff devices
These devices use mouth and airway controls to command an interface. These are typically used by people with very limited to no limb function, and are impacted by the same constraints and requirements as switch devices and keyboard navigation.
Voice command
While users can utilize voice control in a variety of methods, full voice control navigation is another method employed by those with limited vision or mobility. Similar constraints to switch devices or keyboard navigation and screen readers apply.
Barriers to functional accessibility
Mouse-only interactions
Many alternate methods of navigation require that interactions can be performed without a mouse. Examples of interactions that may be classified as “mouse-only” include:
- Dropdown menus that only appear on hover and cannot be reached by keyboard or switch devices.
- Drag-and-drop interfaces with no alternate keyboard support.
- Custom interactive elements that haven’t had keyboard support built into them.
Mouse-only interactions can also be problematic for mobile device and touch screen users. Similar to keyboard navigation, there is no sense of hover in a touch environment—so hover dependent interactions are also more likely to fail for these scenarios.
Missing or invisible focus indicators
When navigating a website via keyboard—or similar alternate navigation device—a visible highlight should appear to show which element is actively selected. Many sites still suppress this indicator for aesthetic reasons, leaving users who rely on alternate navigation tools unable to discern their location within a page.
By default, browsers display a focus outline on all interactive elements. You can leave this as is, or apply custom styles; just make sure the focus state is obvious and draws the user’s attention. Having visible and logically presented focus interactions is one of the most common and most impactful areas of functional accessibility.
Keyboard traps
This occurs when a user’s focus enters an element—such as a modal, widget, or embedded functionality—but cannot escape, or move to another selectable element without using a mouse to do so. A user unable to use a mouse will be effectively barred from the rest of the page. Keyboard traps commonly occur in things like third-party chat widgets, booking tools, and embedded maps.
Small or densely packed targets
A target is the selectable area that triggers an element’s interaction. It’s important that targets be sized large enough and spaced an appropriate distance apart. Otherwise, it can be difficult to accurately trigger with the intended action for any user and especially for those with limited motor precision.
Issues with target size are particularly common on mobile devices as touch interactions are inherently less precise than mouse clicks, and individuals with larger thumbs can struggle to click targets—even without any additional motor or precision difficulties.
Time limits and timed interactions
Users with loss of motor control or users of assistive tools, will typically take longer to interact with page content and complete tasks. Because of this, any forms or sessions that expire after a fixed period of time can create an accessibility barrier. Additional pain points include carousels and auto-advancing content that cannot be paused or controlled by the user. In these instances any users who needs additional time to process, navigate, or input information are effectively penalized.
Why functional accessibility matters for small businesses
Functional accessibility issues can be harder to identify and harder to fix as they are often caused by issues in the structure and code of the website. While they may seem more invisible, their impact can be debilitating. Issues with functional accessibility don’t just make a user’s experience harder, they can make it impossible—essentially disabling a website for someone relying on assistive technology.
The functionality that enables keyboard navigation is particularly critical, as it is a foundational requirement that simultaneously affects screen readers, voice control, and alternate navigation devices.
Many of the technical requirements for functional accessibility and keyboard navigation are aligned with SEO best practices—meaning ignoring these issues has the potential to hurt your business two-fold. However, despite the overlap the requirements are not the same. While improving your website’s functional accessibility is likely to benefit your SEO (and vice versa) it is still important to evaluate the two separately.
Across the board, many functional accessibility issues were unlikely to have been introduced deliberately. Rather, they were likely a result of foundational failures within your default website template, inexperienced development support, or third-party plugins.