Co je Testování přístupnosti? (Příklady)

Co je Testování přístupnosti?

Testování přístupnosti is a type of software testing performed to confirm that an application is usable by people with disabilities, including users with vision, hearing, motor, cognitive, and age-related impairments. It is a subset of testování použitelnosti and verifies that the product works with the assistive technology these users rely on every day.

Assistive technology helps people with disabilities operate a software product. Common examples include:

• Software pro rozpoznávání řeči – Converts spoken words into text that serves as input to the computer.
• Software pro čtení obrazovky – Reads out the text and interface elements displayed on screen.
• Screen magnification software – Enlarges portions of the monitor to make reading easier for users with low vision.
• Specializované klávesnice – Designed for users with motor control difficulties to make typing jednodušší.
• Switch and eye-tracking devices – Allow users with severe motor disabilities to navigate and select interface elements.

Proč Testování přístupnosti?

Důvod 1: Cater to the market of users with disabilities.

According to the World Health Organization, about 1.3 billion people, or roughly one in six worldwide, live with a significant disability.

• 1 in 10 people have a severe disability.
• 1 in 2 people over the age of 65 have reduced capabilities.

Disabilities include blindness, deafness, motor impairments, cognitive conditions, and other long-term health issues. A product that is built to be accessible can reach this large market, and most accessibility defects can be prevented when accessibility testing is made part of the normal software testing life cycle.

Důvod 2: Abide by accessibility legislation.

Governments around the world have passed legislation that requires IT products to be accessible to people with disabilities. Major examples include:

• United States: Americans with Disabilities Act (ADA, 1990) and Section 508 of the Rehabilitation Act.
• United Kingdom: Equality Act 2010 (which replaced the Disability Discrimination Act 1995).
• European Union: European Accessibility Act, which became enforceable for many products and services in June 2025, and standard EN 301 549.
• Australia: Disability Discrimination Act 1992.
• Ireland: Disability Act 2005.
• Canada: Accessible Canada Act 2019.

Accessibility testing is essential to ensure legal compliance in every market where your product is sold.

Důvod 3: Avoid potential lawsuits.

Large companies have been sued repeatedly because their digital products were not accessible. A few prominent cases include:

• National Federation of the Blind (NFB) v. Target (2006, settled 2008).
• NFB v. AOL settlement (1999).
• Robles v. Domino’s Pizza (2019), where the U.S. Supreme Court let stand a ruling that ADA applies to websites and mobile apps.
• Gil v. Winn-Dixie (2017), the first U.S. trial verdict requiring an inaccessible website to be fixed.

Web accessibility lawsuits in the United States have grown every year, with more than 4,000 ADA Title III digital cases filed annually since 2022. Building accessible products from the start avoids these costs and protects the brand.

Která postižení podporovat?

An application must support people with disabilities such as:

Typ postižení	Invalidita Description
Postižení zraku	Complete blindness, color blindness, or low vision. Sensitivity to visual strobe and flashing effects.
Tělesné postižení	Inability to use a mouse or keyboard with one hand. Poor motor skills, including limited hand movement or muscle slowness.
Cognitive Disability	Learning difficulties, poor memory, or trouble following complex scenarios.
Postižení gramotnosti	Reading difficulties such as dyslexia.
Sluchové postižení	Auditory issues including deafness and hearing impairment. Inability to hear sound or to hear it clearly.

Accessibility Standards and Guidelines

Accessibility testing programs rely on a small set of widely adopted standards. Understanding which standard applies to your market is the first step before any test plan is written.

• WCAG 2.2 – Published by the W3C in October 2023, the Web Content Accessibility Guidelines 2.2 are the current global benchmark. They define three conformance levels: A (basic), AA (the legal minimum in most countries), and AAA (highest).
• WCAG 3.0 – A W3C Working Draft that introduces an outcome-based scoring model. It is still under development and has not replaced WCAG 2.2.
• Oddíl 508 – U.S. federal procurement rule that requires electronic and information technology purchased by federal agencies to meet WCAG 2.0 Level AA criteria.
• IN 301 549 – European harmonized standard for ICT accessibility, used to demonstrate compliance with the European Accessibility Act.
• Hlava ADA III – U.S. civil rights law applied to websites and mobile apps of public accommodations; courts commonly use WCAG 2.1 or 2.2 AA as the benchmark.

Most teams treat WCAG 2.2 úroveň AA as their working target because it is both the common legal baseline and a practical engineering goal.

Jak provést Testování přístupnosti?

Accessibility testing can be performed in two ways:

1. Manuál
2. Automatizovaný

Accessibility testing may be challenging for testers who are unfamiliar with disabilities. It is best practice to involve users with disabilities or accessibility specialists who can describe real-world challenges. The techniques below cover the major impairment categories.

1) Postižení zraku

Imagine that you cannot see at all and you need to use the XYZ website. Your only practical option is a screen reader. A screen reader is software that narrates the content on a web page, including text, links, radio buttons, images, and video, so that a blind user can perceive the interface. Popular screen readers include ČELISTI, NVDA, Apple VoiceOver, and Android Odmlouvat.

When you launch JAWS and then open a browser, JAWS announces the page title. If you move focus to the address bar, JAWS says “Address bar” and then reads each character you type. For example, typing google.com produces an announcement like the following:

Address Bar, w, w, w, period, g, o, o, g, l, e, period, c, o, m.
When the page finishes loading, JAWS announces "Google.com home page".
When focus reaches the search field, JAWS announces "Google search, edit".

A screen reader narrates word by word inside text fields, announces links as “link”, and announces buttons as “button”, so that a blind user can identify each control. If a website is poorly built, the screen reader may misidentify elements; for example, a link styled as plain text may be read as content, hiding a critical action from the user. The cost to the business is real lost revenue.

2) Color Blindness

Color blindness means a user cannot perceive certain colors correctly. Red-green color blindness is the most common form. If a website relies heavily on red to convey meaning, a user with red-green color blindness may miss the message.

Design teams should never use color alone to communicate information. A red error button is more accessible when it is also outlined, labeled with an icon, and accompanied by descriptive text. Black and white remain the safest universal palette, and tools such as the Stark plugin or browser color-blindness simulators help reveal problems early.

3) Low Vision

Users with low vision or other retinal conditions need additional support to use the site:

1. Avoid very small text. WCAG recommends a default body size that scales comfortably without zoom.
2. Ensure the layout reflows cleanly when text is enlarged up to 200 percent (a WCAG 2.2 Success Criterion). Lines should not be cut off and content should not overlap.
3. Maintain a minimum contrast ratio of 4.5:1 for normal text and 3:1 for large text.

4) Motor and Other Disabilities

A major accessibility requirement is that the entire site must be operable without a mouse. Every link, button, radio button, checkbox, pop-up, dropdown, and control should be reachable and operable using the keyboard alone.

Například, a user with limited hand mobility may not be able to use a mouse. If checkboxes or links cannot be reached with the Tab key, the user is locked out of those features.

Alternative text should be provided for every image, audio file, and video so that screen readers can convey their meaning. Keyboard shortcuts should be available for important actions, and skip-to-content links should let keyboard users bypass repeated navigation.

Focus must always be visible. When the user presses Tab, the highlighted control should stand out clearly. Visible focus helps users with low vision or color blindness follow the flow of the page and makes navigation predictable for everyone.

Users with hearing disabilities can usually see the visual content of a site, but audio and video pose problems. Every video must include captions, and every audio file must include a transcript or descriptive text. For example, a tutorial video on booking an airline ticket should ship with accurate captions so a deaf user can follow along.

Sample Test Cases for Accessibility Testing

The checklist below is used to sign off accessibility testing for a typical web application. Use it as a starting point and extend it with the WCAG 2.2 success criteria relevant to your product.

1. Are keyboard equivalents provided for every mouse operation and dialog?
2. Does user documentation explain how to operate the application with assistive technology?
3. Is the tab order logical so that navigation flows naturally?
4. Are shortcut keys provided for primary menus?
5. Does the application support all targeted operating systems and screen readers?
6. Is the response time of each screen or page clearly communicated so users know how long to wait?
7. Are all labels written correctly and programmatically linked to their controls?
8. Are color choices flexible and tested against color-blindness simulators?
9. Are images, icons, and emojis used in ways that end users can understand?
10. Does the application provide audio alerts where they are useful?
11. Can the user adjust or mute audio and video controls?
12. Can the user override default fonts for printing and on-screen text?
13. Can the user adjust or disable flashing, rotating, or moving displays?
14. Confirm that color is never used as the only means of conveying information.
15. Is highlighting still visible when system colors are inverted? Test by changing contrast ratios.
16. Are audio and video transcripts or captions available for users who cannot hear?
17. Is training provided for users with disabilities to help them become familiar with the application?
18. Are all interactive controls reachable, operable, and dismissible using a keyboard alone?

How AI is Changing Accessibility Testing

AI je reshaping accessibility testing in three practical ways. First, machine-learning scanners now read the rendered DOM together with computer-vision models to detect issues that rule-based tools miss, such as inappropriate alt text or color combinations that fail in real layouts. Second, generative AI suggests human-readable fixes, including better alt text, clearer error messages, and ARIA attributes for custom components. Third, AI prioritizes findings by user impact, so teams can spend their budget on the issues that matter most. Tools such as Deque axe AI, Evinced, UserWay, and Siteimprove now include AI features. AI does not replace manual screen reader testing or user research with people who have disabilities, but it greatly reduces the manual triage workload and helps accessibility shift left into the development cycle.

Mýty o testování přístupnosti

Following are common myths about accessibility testing along with the facts:

Mýtus: Creating an accessible website is expensive.

Skutečnost: It is not. Considering accessibility during design, together with basic testing, saves money compared with retrofitting and reduces costly rework.

Mýtus: Changing an inaccessible website into an accessible one is too time consuming and expensive.

Skutečnost: You do not have to apply every fix at once. Start with the changes that have the biggest impact on users with disabilities and roll out the rest in later releases.

Mýtus: Accessibility is plain and boring.

Skutečnost: Pages can still be visually rich and attractive while meeting WCAG 2.2 guidelines. The W3C explicitly discourages text-only versions in favor of a single accessible experience for everyone.

Mýtus: Accessibility is only for blind and disabled users.

Skutečnost: Following accessibility guidelines improves overall usability and benefits every user, including those on mobile devices, in bright sunlight, or in noisy environments.

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