Learn what a web accessibility audit is, how WCAG-EM methodology works, the difference between manual and automated testing, and how to hire the right accessibility audit provider for your website.
What Is a Web Accessibility Audit and Why Do You Need One?
Picture this: you open a brand-new retail store, and without realizing it, you place a 12-inch step at the entrance. A significant percentage of your potential customers simply cannot get in. That is exactly what happens with an inaccessible website: you are excluding millions of people without even knowing it.
A web accessibility audit is a systematic evaluation process that analyzes your website to determine whether it meets the Web Content Accessibility Guidelines (WCAG), developed by the World Wide Web Consortium (W3C). It is not about running a quick automated scanner and calling it a day; it is a thorough examination combining automated tools, expert manual review, and ideally, testing with users who have disabilities.
Personally, I believe that an accessibility audit is the single best investment any digital organization can make. According to the WebAIM Million report from 2025, 95.9% of the top one million web pages had automatically detectable accessibility errors. And that only covers a fraction of the total possible barriers.
The WCAG-EM Methodology: The Gold Standard
If you are going to audit a website, you need a serious framework. The WCAG-EM (Website Accessibility Conformance Evaluation Methodology), also from the W3C, is the international standard that defines how to perform a reliable and reproducible evaluation. It is not some consultant's invention; it is the result of years of research and global consensus.
The 5 Steps of WCAG-EM
- Step 1 – Define the scope: you decide which conformance level to evaluate (A, AA, or AAA) and which parts of the site to include.
- Step 2 – Explore the website: you navigate the entire site to understand its structure, technologies used, and key functionalities.
- Step 3 – Select the sample: you choose representative pages covering main templates, critical functionalities, and user processes.
- Step 4 – Audit the sample: you evaluate each page against the applicable WCAG criteria, combining automated tools and manual review.
- Step 5 – Document the results: you produce a detailed report with findings, impact levels, prioritized recommendations, and evidence.
Does that sound like a long process? It is. But would you want your doctor to diagnose you just by glancing at you from across the room? A superficial assessment produces superficial results.
Automated vs. Manual Evaluation: You Need Both
Here is a mistake I see over and over: assuming that an automated scanner is enough. Automated tools like axe by Deque, WAVE by WebAIM, or Siteimprove Accessibility are fantastic for catching obvious technical errors (insufficient contrast, empty alt attributes, unlabeled forms), but they can only identify between 25% and 40% of accessibility issues.
| Aspect | Automated Evaluation | Manual Evaluation |
|---|---|---|
| WCAG criteria coverage | 25-40% | 100% |
| Speed | Minutes | Days/weeks |
| False positives | Frequent | Minimal |
| Semantic context | Does not assess | Assesses fully |
| Real usability | Does not assess | Assesses fully |
| Cost | Low/free | Medium-high |
| User experience | Cannot detect subjective barriers | Detects real problems |
Personally, I always recommend a combined approach: first, an automated sweep to clean up the most basic errors, then a deep manual audit that examines the actual user experience.
Testing with Users with Disabilities: The Component That Makes the Difference
Do you know what separates a good audit from an excellent one? Testing with real users who have disabilities. An expert auditor can follow WCAG standards to the letter, but only a blind user navigating with JAWS or NVDA can tell you whether your checkout form is truly usable. Only a person with reduced mobility using a switch device can reveal that your dropdown menu is a keyboard trap.
Organizations like Fundación ONCE in Spain and the International Association of Accessibility Professionals (IAAP) globally actively promote the inclusion of users with disabilities in evaluation processes. It is not just best practice; it is an ethical obligation.
How many users do you need? According to Jakob Nielsen's research adapted to the accessibility context, with 5 to 8 users representing different types of disabilities (visual, auditory, motor, cognitive) you can detect 85% of critical usability issues.
What Should a Good Audit Report Include?
- Executive summary with the conformance level achieved and an overall score.
- List of barriers classified by WCAG criterion, impact level (critical, high, medium, low), and type of disability affected.
- Screenshots and videos documenting each barrier detected.
- Prioritized technical recommendations with correct code examples.
- Legal risk matrix: which violations could generate penalties under applicable legislation (Directive 2019/882, EN 301 549, ADA, Section 508).
- Action plan with realistic timelines and effort estimates for remediation.
How Much Does a Web Accessibility Audit Cost?
The million-dollar question. Cost depends on many factors: site size, functional complexity, number of templates, whether user testing is included, and whether you need post-remediation support.
| Type of Audit | Price Range | Includes |
|---|---|---|
| Automated only | $0 – $500/year | Scanning with tools like axe, WAVE |
| Basic manual | $1,500 – $4,000 | Expert review of 10-20 pages |
| Full manual + WCAG-EM | $4,000 – $12,000 | Complete methodology, detailed report |
| Full + user testing | $8,000 – $20,000+ | Everything above + testing with 5-8 users |
Is it expensive? Compare it with the cost of an accessibility lawsuit in the United States (the average exceeds $25,000 in legal fees alone) or with losing customers due to an exclusionary experience. Suddenly, the audit looks like a bargain.
How to Hire an Accessibility Audit: Key Criteria
1. Team Certifications and Experience
Look for auditors with IAAP certifications such as CPAC (Certified Professional in Accessibility Core Competencies) or WAS (Web Accessibility Specialist). Ask about their experience in your specific industry: auditing an e-commerce platform is not the same as auditing an educational platform or an online banking portal.
2. Documented Methodology
Require that they follow the WCAG-EM methodology or a documented equivalent. Be wary of anyone who promises a complete audit within 48 hours: it is impossible to do serious work in that timeframe for a site of moderate complexity.
3. Inclusion of User Testing
Ask whether they include testing with users with disabilities or can organize it as an additional service. A provider that does not even mention it probably lacks experience in this area.
4. Post-Audit Support
The audit is only the diagnosis. You need a provider who can also accompany you through remediation: reviewing fixes, re-testing corrected barriers, and training your development team.
