Published by the World Wide Web Consortium (W3C), the Web Content Accessibility Guidelines (WCAG) is the most widely cited international standard for digital accessibility.
WCAG is organized into three levels of conformance: Level A (least strict), Level AA, and Level AAA (most strict). By conforming with Level AA of the most recent version of WCAG — currently WCAG 2.1 — your website can reach a wider audience and provide a better experience for all users. WCAG conformance may also help to protect against litigation — but for some websites, proving conformance can be difficult.
For example: What happens if a website aggregates content from other websites that don’t follow WCAG? What if a site contains an app, plugin, or widget that has accessibility issues? What if the site operates a forum, and some user-generated content doesn’t conform with the guidelines?
In these instances, a website may claim partial conformance as a part of their accessibility statement. Essentially, this statement says that the website doesn’t fully conform with WCAG because of third-party content that the author cannot control.
Here’s how W3C defines a statement of partial conformance:
A "statement of partial conformance" may be made that the page does not conform, but could conform if certain parts were removed. The form of that statement would be, "This page does not conform, but would conform to WCAG 2.0 at level X if the following parts from uncontrolled sources were removed."
A statement of partial conformance can help a website demonstrate its commitment to accessibility while providing users with important information about known barriers. However, it’s important to make sure your accessibility statement is accurate — and that you’ve taken every possible step to create a fully conformant website.
Related: Think Twice Before Writing Your Own Accessibility Statement
Before publishing a statement WCAG conformance, take these steps
Under WCAG, websites aren’t required to publish statements of conformance when they meet their accessibility goals. However, many websites choose to include conformance information as part of their accessibility statements. By telling users that a website meets WCAG standards, authors can build trust with users.
Before claiming any level of WCAG conformance (including partial conformance), make sure you’ve followed these steps:
Audit your website to make sure you’ve addressed WCAG issues
Remember, your accessibility statement is a resource for your users — they’ll assume that it contains accurate info about the steps you’ve taken to improve your site.
Don’t claim WCAG conformance without testing your website thoroughly. Automated tests alone cannot provide proof of conformance; while automated tools can find many WCAG conformance failures, they can’t identify many common issues like inadequate alternative text or inaccessible off-page links.
Third-party accessibility audits can be extremely helpful for earning, maintaining, and proving conformance. Look for a service that uses both manual and automated tests; the Bureau of Internet Accessibility utilizes a four-point hybrid accessibility testing system, which we believe offers the best path to achieving digital compliance.
Try to avoid using third-party content with known accessibility issues
A statement of full conformance is much more effective than a statement of partial conformance, so try to avoid problematic third-party content wherever possible.
Search for widgets, plugins, apps, authentication tools, and other third-party content with strong accessibility features. Read the developer’s accessibility statement — and if their website doesn’t mention accessibility, look for an alternative.
Provide users with specific information about nonconforming content
If you’re writing a statement of partial conformance, tell your users where they might encounter third-party content with potential accessibility issues. For example: “User-created content in our forums might create accessibility issues when accessed with screen readers or other assistive technologies.”
If possible, provide this information throughout your website — not just on your accessibility statement. This can help your users avoid certain content or make proactive accommodations (and they’ll certainly appreciate your effort).
Monitor all third-party content and update your accessibility statement when necessary
Third-party content can affect the accessibility of content you control, so if you have a large or dynamic website, you’ll need to monitor third-party content regularly. For example, a form plugin might be accessible when installed, but an update could introduce a keyboard trap that prevents keyboard-only users from navigating your website. An advertising widget may serve an ad with flashing pictures or poor color contrast, which could create serious usability issues for people with certain conditions.
Of course, monitoring all third-party content can be challenging. Professional accessibility experts can help you create a plan for long-term conformance and identify conformance issues as soon as they occur. For more guidance, read our free Ultimate Guide to Web Accessibility.