Many accessibility audit tools promise to make your website WCAG compliant – and, by extension, compliant with laws like the ADA, Section 508, and EAA. However, can automated tools really make your website fully WCAG compliant?
This is a common concern among those considering automated accessibility tools but doubting their accuracy. In this guide, we’ll provide a clear answer to your question and outline the steps to achieve full WCAG compliance.
Automated tools alone cannot make your website fully WCAG compliant. They cannot assess everything required for full WCAG compliance; some guidelines focus on usability and user experience, which require human judgment.
Here are some areas that automated tools cannot fully assess:
A GDS audit of automated tools found that out of 142 known accessibility issues, even the best tools identified only 30 to 40%. Also, web accessibility expert Karl Groves discovered that only 25 to 33% of WCAG guidelines can be reliably evaluated using automated tools.
To summarise, automated tools can’t detect all WCAG violations, making manual testing essential to address the nuanced issues they miss. To achieve full WCAG compliance, a combination of automated scans and manual checks is necessary.
The amount of accessibility testing that can be automated varies based on the WCAG level you’re aiming to achieve. About 25% of Level A checks, 17% of Level AA, and 23% of Level AAA can be reliably automated.
The table below shows how much of the testing at each level can be automated, how much requires manual verification, and how much must be done manually.
| WCAG Level | Auto | Manual Verification Required | Manual Only |
|---|---|---|---|
| Level A | 25% | 29% | 46% |
| Level AA | 17% | 41% | 41% |
| Level AAA | 23% | 24% | 53% |
As the compliance level rises, the reliance on manual testing increases, with Level AAA requiring over half of the checks to be conducted manually. Therefore, a well-rounded accessibility strategy that combines these three methods is needed to ensure thorough compliance.
This table presents the testability distribution for WCAG Level AA success criteria (S.C.). It shows the percentage of best practices (BPs) that can be checked using automated tools, those requiring manual verification, and those that rely entirely on manual testing.
| S.C. | Total BPs | Auto | Manual Verification Required | Manual Only |
|---|---|---|---|---|
| 1.1.1 | 26 | 31% | 35% | 35% |
| 1.2.1 | 5 | 40% | 0% | 60% |
| 1.2.2 | 3 | 0% | 0% | 100% |
| 1.2.3 | 3 | 0% | 0% | 100% |
| 1.2.4 | 1 | 0% | 0% | 100% |
| 1.2.5 | 2 | 0% | 0% | 100% |
| 1.3.1 | 33 | 18% | 64% | 18% |
| 1.3.2 | 8 | 13% | 75% | 13% |
| 1.3.3 | 3 | 0% | 0% | 100% |
| 1.4.1 | 3 | 0% | 33% | 67% |
| 1.4.2 | 4 | 0% | 0% | 100% |
| 1.4.3 | 1 | 100% | 0% | 0% |
| 1.4.4 | 7 | 71% | 14% | 14% |
| 1.4.5 | 2 | 0% | 50% | 50% |
| 2.1.1 | 8 | 88% | 13% | 0% |
| 2.1.2 | 2 | 0% | 0% | 100% |
| 2.2.1 | 4 | 25% | 0% | 75% |
| 2.2.2 | 2 | 0% | 50% | 50% |
| 2.3.1 | 4 | 50% | 50% | 0% |
| 2.4.1 | 4 | 0% | 100% | 0% |
| 2.4.2 | 2 | 50% | 50% | 0% |
| 2.4.3 | 5 | 0% | 20% | 80% |
| 2.4.4 | 2 | 0% | 50% | 50% |
| 2.4.5 | 1 | 0% | 100% | 0% |
| 2.4.6 | 4 | 50% | 50% | 0% |
| 2.4.7 | 2 | 0% | 100% | 0% |
| 3.1.1 | 1 | 100% | 0% | 0% |
| 3.1.2 | 1 | 0% | 100% | 0% |
| 3.2.1 | 4 | 0% | 75% | 25% |
| 3.2.2 | 3 | 33% | 33% | 33% |
| 3.2.3 | 1 | 0% | 100% | 0% |
| 3.2.4 | 4 | 0% | 25% | 75% |
| 3.3.1 | 2 | 0% | 0% | 100% |
| 3.3.2 | 6 | 50% | 17% | 33% |
| 3.3.3 | 1 | 0% | 0% | 100% |
| 3.3.4 | 2 | 0% | 0% | 100% |
| 4.1.1 | 3 | 100% | 0% | 0% |
| 4.1.2 | 13 | 23% | 69% | 8% |
Begin by performing an automated accessibility audit on your website using WebYes. The tool can quickly identify straightforward issues like missing alt text, improper heading structures, and colour contrast errors, giving you a solid starting point.
After automated scans, WebYes will flag elements requiring manual review. Evaluate these flagged areas and test usability with real-world scenarios, focusing on smooth keyboard navigation and compatibility with screen readers.
Resolve all accessibility issues identified through both automated and manual audits. This comprehensive approach ensures your site meets all WCAG requirements, providing a fully accessible and compliant experience for all users.
For detailed steps, refer to our guide on WCAG compliance.
To make things easier and more efficient for you, here are some best practices to follow when testing and maintaining your website’s accessibility. These tips will help ensure you stay compliant over time while creating a user-friendly experience for everyone.
By following these best practices, you can efficiently maintain accessibility and ensure your website stays compliant as it evolves. This proactive approach not only keeps your site legally sound but also enhances the experience for all users.
An example of something automated accessibility tools cannot test for is logical focus order. They can’t determine if the order flows naturally.
WebYes is the best tool for accessibility testing, as it detects all possible issues an automated tool can identify while flagging items requiring manual review.
No, there is no automated tool currently available that can cover all WCAG guidelines in full. The closest solution is WebYes, which covers approximately 30% of issues.
Article by
Melwyn holds a Bachelor's degree in Computer Science and has been writing professionally for over 4 years. He has a strong background in SEO and is certified in web accessibility from the World Wide Web Consortium (W3C). When he's not writing about website optimisation, you can find him enjoying a game of FIFA or exploring the open world of GTA.
