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WCAG 2.1 | Validator, Checklist, and Live Human Testing


A Web Content Accessibility Guidelines validator is an excellent tool for making your website accessible to a larger audience, but the tool is just one component in the larger process of making your website accessible to people with disabilities.

wcag 2.0 compliance

When conducting a web accessibility evaluation, your organization should also run through an accessibility checklist and conduct human testing to make sure your digital platforms are compliant with accessibility guidelines. Accessibility evaluation tools make it easier to identify and resolve problems, but can’t catch every problem and can trigger warnings when there isn’t a problem.

If you intend to put out a welcome mat for potential customers and clients with disabilities online, you probably realize that it’s essential to offer a fully accessible digital experience. The combination of a WCAG validator, accessibility checklist, and human testing works better than any compliance check on its own.

Using Established Guidelines

The Web Content Accessibility Guidelines are a universally accepted set of rules and recommendations that direct organizations towards full accessibility. Released in June of 2018, the WCAG 2.1 update expands upon the WCAG 2.0 guidelines to keep pace with new technology and evolving human use cases.¹ WCAG compliance standards are based on laws like the Americans with Disabilities Act of 1990 and Section 508.

If you’re concerned about meeting all the compliance needs, the first step is to develop a strategy to assess your current website as it compares to the regulatory needs. Then you’ll want to make a comprehensive list of any changes you need to make to maintain compliance.

All of these upgrades will need to be tested to make certain that they meet standards and are easy for your users to navigate.

There are three methods we recommend using to check your website:

  1. An automated WCAG validator
  2. An accessibility checklist
  3. Human testing

All of these methods have benefits and limitations, which is why we recommend using more than one.

Automated WCAG Validators: A Fast Starting Point

WCAG validators come with all the pros and cons of automation. A web accessibility checker examines a specific feature of a web page, application, or digital document and tests it against a pre-determined set of conditions.

The accessibility tool will rate the test content with a “pass” or “fail” grade. These tools typically return an error report explaining why WCAG validation failed. There are dozens of web accessibility testing tools such as AChecker that can automatically test whether elements of your website are WCAG compliant.² Some may also perform a Section 508 check to ensure legal compliance.

For example, the World Wide Web Consortium, or W3C, the international organization behind the Web Content Accessibility Guidelines, provides a program called Unicorn. This WCAG validator allows you to enter the URL of any web page, get a detailed account outlining where it isn’t WCAG compliant, and learn how you can improve page accessibility.³

Accessibility guidelines and laws aren’t limited to just web browser content: they also include PDFs and other forms of digital documents. Programs like Microsoft Word, Excel, and PowerPoint all feature accessibility tools that can flag potential issues in your documents, spreadsheets, and presentations. For example, Microsoft Word includes a screen reader function that’s ideal for human testing.4

The W3C also maintains a helpful searchable database, the Web Accessibility Evaluation Tools List, featuring WCAG validators from different organizations. A given tool checks accessibility for elements like online color and contrast or alternative text on images. Some are downloadable programs while others run online.

Tools like these are often free and work instantly. However, some tools only test the accessibility of one website component or type of technology.

The Image Example

Often automated tools require human interpretation. The law requires that images that aren’t decorative have an alternative attribute that is meaningful to the image. However, an automated tool will only detect the presence of the alt-text: it requires a human to determine if the text is relevant to the image itself.

WCAG validator tools like alt-text checkers are useful for giving you an idea of the level of accessibility problems with your website. However, you should not depend on them to provide you with a complete list of every single WCAG violation.

Validation tools are useful because they’re instantaneous. They automatically check the website or document and give you a full report of issues that you might need to examine or change. No matter how good the tool is, the tool’s results require human interpretation to rule out false flags and identify additional problems.

WCAG 2.1 Checklists: A Straight-Forward, Deliberate Process

A WCAG checklist is a simple, easy-to-follow, systematic list of web accessibility requirements for WCAG compliance. If you happen to find the full set of Web Content Accessibility Guidelines intimidating or filled with jargon you don’t understand, then a website accessibility checklist is a good place to get started. Download our Must-Have WCAG 2.1 Checklist here.

A checklist may guide you to look at whether the text on your website will still format properly when a user enlarges it. A WCAG checklist can be extremely useful and informative reference that guides your organization through looking at the major accessibility components it needs for compliance. But like the validator, you should know that the checklist is not an exhaustive method.

Your website might meet all the requirements in the list, but that’s in no way a guarantee that there aren’t still major accessibility problems with the site. It’s not a checklist or computer program that’s going to be using your website: it’s real people. Web accessibility-testing checklists help you find and resolve obvious barriers.

Human Testing: The WCAG Compliance Target

No program or checklist can replace web accessibility testing with real human beings. In particular, testing accessibility with people with disabilities provides valuable real-world user feedback. It’s only this kind of evaluation that will uncover usability problems that can’t be identified using automatic validators or by following checklists.

Checking your website yourself can be difficult because you’re overly familiar with the user interface. You designed it yourself so you know where everything is and what it looks like; this makes it difficult for you to identify problems other people may experience.

Having people with disabilities who are unfamiliar with your website is an excellent practice for pinpointing accessibility problems people experience. These can often be things you wouldn’t think of yourself and might not be flagged through an automatic validator or your checklist.

Getting the right people and skills involved makes your accessibility evaluations more effective.5 For example, you’ll learn more about the way a person with a certain disability might use assistive technology and what they’re bumping against when they try to use that technology to visit your website.

A professional consultant will involve a team of experienced human evaluators with a range of disabilities and technologies. They’ll look at all critical aspects of your website, not just a handful, and they’ll have the best chance at catching usability glitches. They’ll also offer you valuable and practical WCAG 2.1 accessibility remediation solutions, regardless of the target compliance level.

The Multi-level Compliance Process

When you use a WCAG validator, a WCAG checklist, human evaluation, or a combination of all three, you’re taking important steps to ensure that people with disabilities have an enhanced online experience when they turn to your website for information, products or services.

Incidentally, you’re also complying with laws including the ADA, which protect people with disabilities from discrimination and accessibility barriers.6,7 Many regulations, like the refreshed Section 508 and the Air Carrier Access Act, use the WCAG 2.1 guidelines and the technical requirements for web accessibility. Adhering to them allows organizations to achieve and maintain compliance with required standards and regulations.

The best part of making your website compliant with WCAG 2.1 is you’re making it a better experience for all your visitors. Accessibility enhancements also help people who are older, inexperienced with the Internet, and less fluent in English. In other words, offering an accessible website means putting out a welcome mat for everyone.

Does your website meet all the accessibility requirements for every visitor? Find out by requesting a personalized demo from the experts at eSSENTIAL Accessibility.


  1. Web Content Accessibility Guidelines (WCAG) 2.1, W3C, 2018
  3. Unicorn – WSC’s Unified Validator
  4. Use a Screen Reader to Explore and Navigate Word, Microsoft
  5. Evaluating Web Accessibility Overview, W3C
  6. ADA Update: A Primer for State and Local Governments,
  7. A Guide to Disability Rights Laws,