How to Conduct a Web Accessibility Audit
An accessibility audit is the most effective way to understand how well your website serves people with disabilities. This guide walks you through the entire process, from initial automated scanning to manual testing, issue documentation, and ongoing monitoring. Whether you are responding to a legal requirement, preparing for a formal compliance review, or simply building a more inclusive product, the steps below give you a clear and repeatable process to follow.
What Is an Accessibility Audit?
An accessibility audit is a systematic evaluation of a website or web application against established accessibility standards, most commonly the Web Content Accessibility Guidelines (WCAG) published by the W3C. The audit examines how pages, components, and interactions work for people who use assistive technologies such as screen readers, keyboard navigation, switch devices, and voice control, as well as people with visual, auditory, motor, and cognitive disabilities.
The purpose of an audit is to identify barriers -- places where your website prevents or significantly hinders access for people with disabilities. These barriers range from missing image descriptions that make content invisible to screen reader users, to color contrast ratios that make text unreadable for people with low vision, to keyboard traps that make it impossible for users who cannot use a mouse to navigate past certain elements.
An audit produces a detailed inventory of issues, each mapped to specific WCAG success criteria, rated by severity, and accompanied by a recommendation for remediation. This inventory becomes the foundation for a prioritized fix plan. Without an audit, accessibility work tends to be ad hoc and reactive. With one, you have a clear picture of where you stand and a roadmap for where to go.
Automated vs Manual Testing
One of the most important things to understand about accessibility testing is that no single approach covers everything. Automated tools can reliably detect approximately 30-40% of WCAG success criteria. That is genuinely useful -- automated scans are fast, consistent, and catch a wide range of common violations. But the remaining 60-70% of accessibility issues require human judgment to identify.
The most effective accessibility programs use both approaches together. Automated tools serve as the first line of defense, running frequently to catch regressions and obvious violations. Manual testing goes deeper, evaluating the actual user experience for people with disabilities. Neither approach is optional if you want meaningful accessibility coverage.
Here is a practical breakdown of what each approach handles best:
Automated Tools Excel At
- Color contrast ratio failures
- Missing image alt text
- Invalid or misused ARIA attributes
- Heading hierarchy violations
- Missing form labels
- Empty links and buttons
- Missing document language
- Duplicate element IDs
Manual Testing Required For
- Whether alt text is actually meaningful
- Logical keyboard navigation order
- Full screen reader user experience
- Cognitive load and content clarity
- Context-dependent link purposes
- Complex widget interaction patterns
- Reading order in dynamic content
- Timeout and animation preferences
Bottom line: Automated scanning is essential for catching the issues machines can identify, but it is not a substitute for manual testing. Relying solely on automated results will leave the majority of potential accessibility barriers undetected. Plan for both in your audit process.
Step-by-Step Audit Process
A thorough accessibility audit follows a structured process that combines automated scanning with targeted manual testing. Follow these eight steps to evaluate your site comprehensively and produce actionable findings.
Define Scope
Determine which pages to audit, which WCAG conformance level to target (typically Level AA), and which user flows are most critical. Start with high-traffic pages, key conversion paths, and any pages that handle essential tasks like registration, checkout, or account management. Document the scope so your findings are tied to specific pages and criteria.
Run an Automated Scan
Use CompliaScan or a similar automated tool to perform an initial sweep of your target pages. Automated scans will quickly flag issues like missing alt text, color contrast failures, ARIA errors, and structural problems. This gives you a baseline and highlights the low-hanging fruit. Run scans across representative page templates rather than every single URL -- if your product pages share a template, scanning a few is sufficient.
Keyboard Testing
Put your mouse aside and navigate every page using only the keyboard. Tab through all interactive elements (links, buttons, form fields, menus, modals) and verify that: focus is visible at all times, the tab order follows a logical reading sequence, no element traps focus, all functionality is reachable, and dropdown menus and modal dialogs can be opened, navigated, and closed. Pay special attention to custom widgets, date pickers, and rich-text editors.
Screen Reader Testing
Test with at least one screen reader to understand the auditory experience of your site. NVDA (free, Windows) or VoiceOver (built-in, macOS/iOS) are the most accessible options for testing. Navigate through headings, landmarks, links, and forms. Verify that images have useful descriptions, that ARIA labels provide context, that dynamic content changes are announced, and that form errors are communicated clearly. Listen for anything that is confusing, missing, or redundant.
Visual Inspection
Zoom your browser to 200% and verify that all content reflows correctly without horizontal scrolling, no text is truncated or overlapping, and interactive elements remain usable. Check that spacing and layout remain functional at larger text sizes. Also test with high-contrast mode enabled and verify that information is not conveyed by color alone -- for example, error states should use icons or text in addition to a red color.
Forms and Error Handling
Test every form on the audited pages. Submit forms with empty required fields and incorrect data. Verify that error messages are clearly associated with the corresponding input, that errors are announced to screen readers, that instructions are available before the user starts filling in the form, and that the user can recover from mistakes without losing their data. Check that autocomplete attributes are present for common fields like name, email, and address.
Document Findings with Severity Ratings
Record each issue with its WCAG success criterion reference, the page and element where it occurs, a description of the problem and its user impact, and a severity rating (critical, serious, moderate, or minor). Use screenshots or screen recordings to make issues reproducible. A consistent format makes it easier to track progress and communicate with development teams.
Prioritize and Create a Remediation Plan
Group issues by severity and create a phased remediation plan. Address critical issues first (anything that blocks access entirely), then serious issues (significant barriers), followed by moderate and minor issues. Assign each issue to the responsible team or developer, set target dates, and establish a process for retesting after fixes are applied. The goal is not perfection on day one -- it is measurable, continuous improvement.
Tools You Need
A well-equipped accessibility audit uses a combination of automated scanners, assistive technologies, browser extensions, and specialized utilities. You do not need to purchase expensive software -- many of the best tools are free or built into your operating system. Here is what to include in your toolkit.
Automated Scanners
- CompliaScan -- Cloud-based WCAG 2.2 scanner with severity ratings, fix suggestions, and monitoring. Free tier available.
- axe DevTools -- Industry-standard accessibility engine by Deque, available as a browser extension and CI/CD integration.
- Lighthouse -- Built into Chrome DevTools. Includes an accessibility category powered by axe-core. Good for quick spot checks.
Screen Readers
- NVDA -- Free, open-source screen reader for Windows. The most widely used free screen reader and an excellent choice for testing.
- VoiceOver -- Built into macOS and iOS at no cost. Essential for testing on Apple platforms and Safari.
- JAWS -- The most popular commercial screen reader. Widely used in enterprise and government settings. Offers a 40-minute trial mode.
Browser Extensions
- axe DevTools Extension -- Runs axe-core directly in your browser with a clean interface for inspecting issues in context.
- WAVE -- WebAIM's browser extension that provides visual overlays highlighting accessibility errors, alerts, and structural elements directly on the page.
- HeadingsMap -- Visualizes the heading structure of a page in a sidebar, making it easy to spot hierarchy issues.
Color and Contrast Tools
- WebAIM Contrast Checker -- Enter foreground and background colors to instantly see whether they meet WCAG AA or AAA contrast requirements.
- Colour Contrast Analyser -- Desktop application by TPGi with an eyedropper tool for testing contrast on any screen content.
- Stark -- Figma, Sketch, and Adobe XD plugin for checking contrast and simulating color vision deficiencies during design.
Common Issues Found in Accessibility Audits
Year after year, accessibility studies report the same categories of issues dominating audit findings. The WebAIM Million study, which analyzes the home pages of the top one million websites, consistently shows that a small number of issue types account for the vast majority of detected violations. If you fix these ten issues across your site, you will eliminate most of the barriers your users face.
Here are the ten most commonly found accessibility issues, in roughly the order of how frequently they appear:
- 1
Missing Alternative Text
Images without alt attributes or with empty alt text when the image conveys meaningful content. Screen reader users have no way to understand what the image represents.
- 2
Low Color Contrast
Text that does not meet the minimum contrast ratio of 4.5:1 for normal text or 3:1 for large text. Affects users with low vision, color blindness, and anyone viewing screens in bright environments.
- 3
Missing Form Labels
Form inputs without associated label elements or accessible names. Screen readers cannot tell users what information a field expects, making forms unusable for blind and low-vision users.
- 4
Empty Links
Links that contain no text content and no accessible name, often caused by icon-only links missing an aria-label or by wrapping an image in a link without alt text. Users hear "link" with no indication of where it goes.
- 5
Missing Document Language
Pages without a lang attribute on the html element. Screen readers rely on this to select the correct pronunciation rules. Without it, content may be read with the wrong language voice.
- 6
Empty Buttons
Buttons with no text content and no accessible name, frequently occurring with icon-only buttons that lack aria-label attributes. Users cannot determine what action the button performs.
- 7
Missing Skip Navigation
Pages without a skip navigation link that allows keyboard users to bypass repeated header and navigation content. Without it, users must tab through dozens of links on every page before reaching the main content.
- 8
Incorrect Heading Hierarchy
Headings that skip levels (jumping from h1 to h3) or pages with multiple h1 elements. Screen reader users rely on heading structure to navigate and understand content organization.
- 9
Missing ARIA Labels on Interactive Elements
Custom interactive components (tabs, accordions, dialogs, menus) that lack appropriate ARIA roles, states, and properties. Assistive technology cannot convey the purpose or current state of these elements.
- 10
Keyboard Traps
Interactive elements or components that capture keyboard focus and do not allow users to tab away. Modal dialogs, embedded media players, and third-party widgets are common sources. This completely blocks keyboard-only users from proceeding.
Remediation Priorities
Once your audit is complete and you have a list of issues, the next question is: where do you start? Attempting to fix everything at once is rarely practical, especially on large sites. An impact-based prioritization framework helps you direct effort where it matters most -- toward the issues that cause the greatest harm to the greatest number of users.
The standard approach is to group issues into severity tiers based on their impact on the user experience. This is not about WCAG conformance level (A, AA, AAA) alone -- a Level A issue that affects a rarely used feature may be less urgent than a Level AA issue on your checkout page. Prioritization should weigh both the severity of the barrier and the importance of the affected content.
Critical -- Fix Immediately
Issues that completely block access for one or more user groups. Keyboard traps that prevent navigation past a component. Missing text alternatives for essential content such as form instructions or error messages. Interactive elements that cannot be reached or activated without a mouse. Authentication flows that exclude users of assistive technology. These issues mean some users simply cannot complete core tasks on your site. They should be fixed as soon as possible, ideally within days.
Serious -- Fix Within Weeks
Issues that create significant barriers but do not completely prevent access. Low color contrast that makes text very difficult to read. Missing form labels that force screen reader users to guess what fields require. Lack of visible focus indicators that make keyboard navigation confusing. Heading hierarchies that skip levels, making page navigation disorienting. These issues substantially degrade the experience for affected users and should be addressed in the first sprint or two of remediation work.
Moderate -- Fix Within a Month
Issues that cause inconvenience or confusion but do not prevent task completion. Missing skip navigation links that require extra tabbing. Decorative images with unnecessary alt text that clutter the screen reader experience. Minor heading order inconsistencies on secondary pages. Redundant ARIA attributes that do not cause functional problems but represent code quality issues. These should be addressed as part of normal development cycles.
Minor -- Fix When Possible
Issues that represent best practice improvements rather than clear barriers. Slight contrast ratio shortfalls on non-essential decorative text. Minor inconsistencies in link purpose descriptions. HTML validation warnings that do not affect assistive technology interpretation. These can be picked up during regular code reviews, refactoring, or when working on related components.
Ongoing Monitoring
A one-time accessibility audit is a snapshot, not a solution. Websites change constantly -- new features are built, content is updated, third-party scripts are added, design systems evolve. Each change has the potential to introduce new accessibility issues. Without a system for ongoing monitoring, the work you put into an initial audit gradually erodes as the codebase moves forward.
Effective ongoing monitoring has three components. First, automated scanning on a regular schedule (weekly or after each deployment) catches regressions immediately. Second, integrating accessibility checks into your CI/CD pipeline prevents issues from reaching production in the first place. Third, periodic manual reviews (quarterly or semi-annually) catch the issues that automated tools cannot detect and provide a human perspective on the overall user experience.
The organizations with the strongest accessibility track records treat it as an ongoing quality metric, like performance or security -- not as a one-time project. They monitor continuously, fix regressions quickly, and include accessibility requirements in their definition of done for new features.
Start Monitoring Your Site Today
Run a free accessibility scan to establish your baseline. See where your site stands against WCAG 2.2 Level AA and get actionable recommendations for improvement.
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