Alt Text (Alternative Text)
// Definition
A text description provided via the HTML alt attribute on img elements that conveys the meaning or function of an image to users who cannot see it — including screen-reader users and users with images disabled. Meaningful images require descriptive alt text that communicates the content or purpose of the image, not its appearance. Decorative images (pure visual embellishment) should use an empty alt attribute (alt="") so screen readers skip them entirely. QA testers check that every meaningful image has accurate, concise alt text, decorative images are marked correctly, and complex images (charts, infographics) have extended descriptions.
// Related terms
Screen Reader
Assistive technology software that converts on-screen content into synthesised speech or Braille output, enabling users who are blind or have low vision to navigate and interact with digital interfaces. Common screen readers include NVDA and JAWS (Windows), VoiceOver (macOS and iOS), and TalkBack (Android). QA testers use screen readers to verify that interactive elements have meaningful names, heading and landmark structure is navigable, dynamic content changes are announced, and no information is conveyed visually only.
Semantic HTML
The practice of using HTML elements according to their intended meaning — heading elements (h1–h6) for headings, button for interactive controls, nav for navigation regions, main for the primary content area — rather than using generic div and span elements for everything. Semantic elements convey role, structure, and sometimes state to browsers, search engines, and assistive technologies without requiring additional ARIA attributes. QA testers check that pages use a logical heading hierarchy, landmark regions are present, and interactive controls use native elements rather than div or span with click handlers.
Accessibility
The practice of designing and testing software so it is usable by people with a wide range of abilities — including users who rely on screen readers, keyboard navigation, voice control, switch access, or high-contrast display modes. In QA, accessibility testing involves both automated scanning and manual verification. Automated tools (axe, Lighthouse, Accessibility Scanner for Android, Accessibility Inspector for iOS) catch structural issues such as missing labels, insufficient colour contrast, and incorrect ARIA roles — typically around a third of all accessibility issues. The remaining two-thirds require testing with actual assistive technologies: VoiceOver on iOS, TalkBack on Android, NVDA or JAWS on Windows. WCAG 2.1 AA is the most widely referenced standard; Level AA compliance is required by law in many jurisdictions (ADA, EN 301 549, AODA). Integrating accessibility checks into CI — for example, running axe as part of a Playwright or Selenium test suite — prevents regressions from being merged undetected.