What are assistive technologies?

Assistive technology is a broad term for tools that increase, maintain, or improve a person’s ability to perform a task. In a digital setting, these tools may help someone perceive content, move through an interface, communicate, or enter information.

A person may use assistive technology because of a permanent disability, a changing condition, an injury, or a temporary limitation. The choice of technology is personal. Two people with similar disabilities may use entirely different tools or browsing methods.

Assistive technology also works alongside accessible design rather than replacing it. A screen reader cannot reliably explain an unlabeled form field, for example, unless the webpage provides a useful programmatic label.

Common types of assistive technology

People use many combinations of hardware, software, browser settings, and operating system features. Common examples include:

• Screen readers, which convert text and interface information into synthesized speech or braille.
• Refreshable braille displays, which present digital text through moving braille cells that can be read by touch.
• Screen magnification software, which enlarges content and may adjust contrast, pointer appearance, or focus presentation.
• Voice recognition software, which allows a person to navigate, select controls, dictate text, and issue commands through speech.
• Alternative keyboards and pointing devices, which provide input methods suited to a person’s movement, reach, strength, or coordination.
• Switch controls, which allow navigation and selection through one or more switches rather than a conventional keyboard or mouse.
• Eye-tracking systems, which use eye movement to control a pointer, keyboard, or communication interface.
• Reading and literacy tools, which may read text aloud, highlight words, simplify presentation, or support comprehension.

Not every accessibility need involves a specialized device. A person with color vision deficiency may rely primarily on a website’s color choices, labels, patterns, and contrast. Someone with low vision may use browser zoom rather than dedicated magnification software. Accessible content should support this variation instead of assuming one standard user or tool.

How assistive technologies interpret webpages

A webpage has both a visual presentation and an underlying structure. Browsers parse its HTML into the Document Object Model, commonly called the DOM. The browser then uses native HTML semantics and other available information to build an accessibility tree.

The accessibility tree can expose information such as:

• the role of an element, such as a heading, link, button, or checkbox;
• the element’s accessible name;
• its current state, such as checked, expanded, selected, or disabled;
• its value, when a value is relevant;
• relationships between controls, labels, instructions, and regions.

Assistive technologies can use this information to present an interface in another form. A screen reader user may navigate directly among headings. A voice control user may activate a button by speaking its accessible name. A switch user may move sequentially through focusable controls.

This is why visual appearance alone is not enough. Text that merely looks like a heading may not be exposed as a heading. A clickable graphic may not be identified as a button. Placeholder text may disappear without leaving a durable label for a form field.

Why semantic HTML matters

Semantic HTML communicates what an element is, not only how it should look. Native elements such as <button>, <a>, <input>, and properly ordered headings provide established browser behavior and accessibility information.

For example, a native button generally provides:

• a button role;
• keyboard focus;
• activation with expected keyboard commands;
• an accessible name when its text or label is provided;
• consistent information for the browser’s accessibility tree.

A generic <div> styled to resemble a button does not automatically provide these behaviors. Developers must recreate them carefully, and incomplete recreations are common.

Other structural choices matter as well:

• A logical heading hierarchy helps people understand and navigate the page.
• Real lists expose the number and relationship of list items.
• Explicit form labels identify the purpose of input fields.
• HTML landmarks identify major regions such as navigation, main content, and complementary information.
• Descriptive link text explains where a link leads without requiring the surrounding paragraph.
• Useful alternative text communicates the purpose or content of meaningful images.

How ARIA can help assistive technologies

Accessible Rich Internet Applications, usually shortened to ARIA, is a set of attributes that can add accessibility information to web interfaces. ARIA can define roles, names, states, properties, and relationships that are not adequately expressed through native HTML alone.

For instance, an expandable control may use aria-expanded="false" or aria-expanded="true" to communicate its current state. An icon-only button may need an accessible name that explains its action.

ARIA should be used carefully. It changes what assistive technologies may be told about an element, but it does not automatically add behavior. Adding role="button" to a generic element does not provide keyboard focus, Enter and Space key handling, or proper state management.

When a native HTML element already provides the necessary meaning and interaction, it is usually the more dependable choice. This principle is explored further in When ARIA Is Unnecessary: Let Native HTML Do the Work.

Incorrect ARIA can be worse than no ARIA because it may create a conflict between an interface’s announced meaning and its actual behavior. The goal is not to add as many accessibility attributes as possible. The goal is to expose accurate information.

Assistive technology and Section 508

Section 508 is part of the United States Rehabilitation Act. It requires federal agencies to make their information and communication technology accessible to people with disabilities. Its requirements can also affect contractors and vendors that provide technology to federal agencies.

Section 508 is not a universal law governing every website, and legal obligations depend on the organization and context. However, the technical practices associated with Section 508 frequently improve compatibility with assistive technologies.

These practices include:

• providing keyboard access to interactive features;
• labeling controls and form fields;
• preserving meaningful reading and focus order;
• providing text alternatives for meaningful non-text content;
• not relying on color alone to communicate information;
• providing captions and other alternatives for multimedia;
• communicating errors and status changes accessibly.

The Web Content Accessibility Guidelines, or WCAG, provide a broader technical framework used by many organizations and accessibility policies. Section 508 and WCAG are related, but they are not interchangeable terms.

Practical examples of accessible design

A screen reader user navigates by headings

A sighted reader can scan differences in font size, spacing, and weight. A screen reader user may instead open a list of headings and move directly to the relevant section. If headings are missing, vague, or selected only for their visual size, that navigation pathway becomes less useful.

A voice control user activates a button by name

Suppose a visible button says “Search,” but its accessible name is “Submit.” A person using voice control may say “Click Search” and receive no response because the spoken command does not match the programmatic name. Keeping visible labels and accessible names aligned makes controls easier to identify and operate.

A keyboard user moves through a form

A person who does not use a mouse may press the Tab key to move among controls. Each interactive element needs a visible focus indicator and a logical place in the focus order. A calendar, menu, or dialog that traps focus or skips important controls may prevent the person from completing the task.

A person with low vision enlarges the page

When content is zoomed, rigid layouts can cause text to overlap, disappear, or require excessive horizontal scrolling. Responsive layouts and flexible text containers help the page remain understandable at larger sizes.

A person cannot distinguish a color-coded error

A red border alone may not communicate that a form field contains an error. A clear text message, an error summary, and a programmatic association between the message and its field provide information that does not depend on color perception.

An image carries important meaning

A chart, diagram, product image, or instructional photograph may require alternative text or a nearby text explanation. A decorative flourish may need an empty alt attribute so a screen reader can ignore it. Effective alt text depends on the image’s purpose in context rather than a mechanical description of every visible detail.

Testing with assistive technologies

Automated accessibility tools can identify some problems, including missing labels, certain contrast failures, and invalid attribute combinations. They cannot determine every aspect of meaning, usability, or interaction.

Useful manual checks include:

• navigating the entire page with a keyboard;
• confirming that keyboard focus remains visible;
• reviewing the heading outline and landmark structure;
• checking form labels, instructions, errors, and status messages;
• zooming and reflowing the page at different viewport sizes;
• reviewing content without color cues;
• testing important workflows with representative screen readers or other assistive technologies.

Testing with a screen reader can reveal structural problems, but briefly operating one does not reproduce the knowledge or experience of a person who uses it every day. When possible, evaluation should include people with disabilities and experienced assistive technology users.

It is also important to test more than one browser and assistive technology combination when the audience and project warrant it. Support can vary because accessibility depends on several interacting layers: the webpage, browser, operating system, accessibility API, assistive technology, and user settings.

The relationship between assistive technology, SEO, and retrieval

Assistive technology is not an SEO technique. Accessibility should not be reduced to a ranking tactic or justified only through search visibility.

There is still a meaningful structural relationship. Clear headings, descriptive links, semantic HTML, text alternatives, and understandable page organization can help people navigate content while also giving browsers and retrieval systems clearer signals about its meaning.

The overlap exists because both accessibility and information retrieval benefit from explicit, coherent structure. Their purposes are not identical, and one does not guarantee the other. A page can be discoverable without being accessible, while an accessible page may still need stronger writing or information architecture.

The more durable principle is simple: communicate meaning in forms that do not depend on one sense, one input device, or one mode of presentation.

Frequently asked questions

Is a screen reader the same as text-to-speech software?

Not exactly. Both can speak text aloud, but a screen reader also communicates interface structure, roles, names, states, and navigation information. Text-to-speech tools may focus primarily on reading selected or visible text.

Does adding ARIA make a website accessible?

No. ARIA can provide important accessibility information, but it does not repair unclear content, missing keyboard behavior, poor focus management, insufficient contrast, or inaccessible interaction design. Native HTML should be used where it already provides the needed semantics and behavior.

Do only blind people use assistive technologies?

No. Assistive technologies support people with many kinds of visual, auditory, mobility, speech, cognitive, and neurological disabilities. People may also use them because of injuries, changing abilities, or temporary conditions.