Accessibility Testing: A Beginner's Guide for Manual Testers
In today's digital-first world, building software that everyone can use isn't just a nice-to-have—it's a fundamental requirement. Accessibility testing is the practice of ensuring your website or application is usable by people with a wide range of abilities and disabilities, including visual, auditory, motor, and cognitive impairments. For manual testers, it's a critical skill that moves quality assurance beyond mere functionality into the realm of inclusive design. This guide will walk you through the core principles, tools, and hands-on techniques you need to start integrating a11y testing (the common numeronym for accessibility) into your daily workflow, with a strong focus on the globally recognized WCAG (Web Content Accessibility Guidelines) standards.
Key Stat: According to the World Health Organization, over 1.3 billion people experience significant disability. That's roughly 16% of the global population—a massive user base you cannot afford to exclude from your digital products.
Why Accessibility Testing is Non-Negotiable
Beyond the clear ethical imperative, there are compelling legal and business reasons to prioritize accessibility. Laws like the Americans with Disabilities Act (ADA) in the U.S. and the European Accessibility Act have led to a surge in litigation against companies with inaccessible websites. From a business perspective, inclusive design expands your market reach, improves SEO (search engines love accessible code), and often enhances the user experience for everyone.
As a manual tester, you become the advocate for users who might otherwise be overlooked. Your role is to simulate diverse user experiences and identify barriers that automated tools can miss.
Understanding the Foundation: WCAG Guidelines
The Web Content Accessibility Guidelines (WCAG) are the definitive international standard. They are built on four foundational principles, often remembered by the acronym POUR.
The Four POUR Principles of WCAG
- Perceivable: Information and user interface components must be presentable to users in ways they can perceive. This covers alternatives for non-text content (like alt text for images), captions for videos, and content that can be presented in different ways without losing information.
- Operable: User interface components and navigation must be operable. This includes keyboard accessibility, giving users enough time to read and use content, and avoiding content that causes seizures or physical reactions.
- Understandable: Information and the operation of the user interface must be understandable. This means text is readable, content appears and operates in predictable ways, and users are helped to avoid and correct mistakes.
- Robust: Content must be robust enough to be interpreted reliably by a wide variety of user agents, including assistive technologies like screen readers. This hinges on using clean, standard-compliant code.
WCAG has three levels of conformance: A (minimum), AA (standard target for most legal requirements), and AAA (enhanced). Most organizations aim for WCAG 2.1 AA as a baseline.
Essential Tools for the Manual Accessibility Tester
While your human judgment is irreplaceable, these tools will supercharge your a11y testing process.
1. Browser Developer Tools & Extensions
- axe DevTools (by Deque): A free browser extension (Chrome, Firefox, Edge) that integrates into your DevTools. It's excellent for running quick automated scans and learning about specific failures.
- WAVE Evaluation Tool: A fantastic visual extension that overlays icons and indicators directly onto your webpage, showing structural elements, ARIA attributes, and errors. Perfect for visual learners.
- Lighthouse (in Chrome DevTools): Built directly into Chrome. Its accessibility audit provides a score and a clear list of checks passed and failed, with links to documentation.
2. Screen Readers: The Critical Manual Tool
To truly understand the user experience, you must test with a screen reader. You don't need to be an expert, but learning the basics is crucial.
- NVDA (Windows, Free): The go-to free screen reader for testing. Pair it with Firefox for good compatibility.
- VoiceOver (macOS/iOS, Free): Built into all Apple devices. Essential for testing on the Apple ecosystem.
- JAWS (Windows, Paid): Widely used in the corporate world. You can use the free 40-minute trial mode for testing.
Actionable Tip: Start by navigating a simple page using only the screen reader and keyboard (Tab, arrow keys). Listen to how page structure, links, and buttons are announced.
Core Manual Testing Techniques & Checklists
Here is a hands-on checklist for key areas of manual accessibility testing. Perform these without any automated tools first.
1. Keyboard-Only Navigation
Unplug your mouse. Can you complete all critical tasks?
- Tab through all interactive elements (links, buttons, form fields).
- Is there a visible focus indicator (a highlight) showing where you are?
- Does the tab order follow a logical, visual sequence?
- Can you access and operate all dropdowns, modals, and widgets using the keyboard (often with Enter, Space, Arrow keys)?
- Check for "keyboard traps" where you can Tab into a component but cannot Tab out.
2. Visual and Textual Clarity
- Color Contrast: Use the WAVE or axe tools to check, but also visually inspect. Can text be easily read against its background? Pay special attention to grey-on-grey designs.
- Text Resizing: Use browser zoom (Ctrl/Cmd + "+") to 200%. Does the layout reflow without horizontal scrolling? Does content get clipped or overlapped?
- Non-Text Content: Do all informative images have descriptive alt text? Are decorative images marked with empty alt (`alt=""`)? Do complex charts have long descriptions?
3. Forms and Error Handling
- Is every form field programmatically associated with a visible label?
- When you submit a form with errors, are the errors clearly announced to screen reader users?
- Do error messages suggest how to fix the problem? (e.g., "Password must contain at least 8 characters" vs. "Invalid password").
Real Example: Testing a "Subscribe" button. An automated tool might see a button with text. As a manual tester, you check: Can it be reached via Tab? Does the screen reader announce its purpose (e.g., "Subscribe button")? Does it have sufficient color contrast? If it's an icon button, does it have an `aria-label` like "Subscribe to newsletter"?
Integrating Accessibility into Your QA Process
Accessibility shouldn't be a final-phase checkbox. To be effective, it must be "shifted left" into the entire development lifecycle.
- In Requirements & Design: Advocate for accessibility requirements (like WCAG AA) to be included in user stories and design specs. Review wireframes for semantic structure and color contrast.
- During Development: Partner with developers. Use shared checklists and perform early checks on feature branches.
- In Test Cases: Write specific accessibility test cases. For example: "Verify the new modal dialog can be opened and closed using keyboard-only navigation and is announced correctly by NVDA."
Building a career in modern QA requires a blend of manual insight and technical knowledge. To build a rock-solid foundation in the principles that underpin both functional and non-functional testing, including accessibility, consider our comprehensive Manual Testing Fundamentals course.
Common Accessibility Pitfalls to Avoid
- Poor Semantic HTML: Using a `<div>` for a button instead of a `<button>`. Screen readers rely on proper HTML tags (like `<header>`, `<nav>`, `<main>`) to convey page structure.
- Missing or Poor Alt Text: "image.jpg" is useless. "Close button" is okay. "Close registration modal dialog" is descriptive and contextual.
- Inaccessible Dynamic Content: Updating page content (via AJAX) without notifying screen reader users. Use ARIA live regions (`aria-live="polite"`) appropriately.
- Over-reliance on Color: "Click the red button to delete" is problematic for color-blind users. Always pair color with text or icons.
Your Journey as an Inclusive QA Professional
Starting accessibility testing can feel overwhelming, but begin with one technique at a time. Master keyboard navigation one week, then learn the basics of a screen reader the next. Your unique perspective as a manual tester—focusing on user experience, context, and intuition—is exactly what makes you invaluable in achieving true inclusive design.
The most sought-after testers today are those who can bridge the gap between manual exploratory testing and technical, automated verification. To master this blend and become a full-spectrum QA engineer capable of ensuring both functional robustness and accessibility compliance, explore our advanced Manual and Full-Stack Automation Testing program.