Conforming alternate version

In practice

The two routes nobody quotes are the ones that put the accessible version at the front door. WCAG explains what it means for the non-conforming version to be reachable only from the conforming one. The answer is a mechanism such as a conditional redirect, which stops anybody loading the non-conforming page unless they arrived from the conforming version. So a site can lead with the version that conforms and keep the other one behind it, and no link on the non-conforming page is needed at all. That pattern is sanctioned rather than tolerated.

The modern shape of this is a setting rather than a second site. Setting a user preference inside the content to produce a conforming version counts as a way of reaching one, as long as the control that sets the preference is itself accessibility supported. A simplified view or a high-contrast scheme that produces a conforming page, reached by a toggle a keyboard can operate and a screen reader can name, is a conforming alternate version. That is a long way from the text-only mirror the phrase usually conjures.

The rest of the conditions are looser than people assume and the upkeep is worse. It does not have to match page for page. It does not even have to sit on your own site, as long as it is as freely available as the version it replaces. That rules out putting the accessible one behind a login while the other one is public. Several alternate versions can exist for different environments and only one of them has to be fully conformant. Where it gets expensive is language, because every language you publish in needs its own alternate version. An auditor has to test it too, so a claim resting on one hands them a second product to evaluate. And a UK public body that offers one has to describe it in its accessibility statement.

One thing it is not is a summary. Supplemental content sits alongside a page to help people understand it, and a plain-language summary next to a dense article is exactly that. That summary is not doing nothing, because supplemental content is one of the two ways to satisfy the reading level rule at Level AAA. What it is not doing is standing in for the page, and standing in is the whole job of an alternate version.

Why it matters

This is the one place the standard lets a page fail and still conform, so it is worth knowing precisely rather than roughly. State the fourth requirement too narrowly and you rule out two legitimate patterns, including the conditional redirect W3C explicitly sanctions. Drop the same-language condition from the second requirement and you can ship one alternate version for a site that publishes in five, which leaves the other four languages with nothing standing in for them. Our own position sits next to the standard rather than inside it, and we will say it plainly. Building one version of the thing that works for everybody beats building a lesser second one. The second one is another product to keep current, and it tells disabled customers which of the two they were offered.

Where this shows up on the site

• Universal design
• Conformance

Related terms

• Universal designUniversal design is the idea that one design should work for as many people as possible without anybody needing a special version or a separate adaptation.
• ConformanceConformance means satisfying all the requirements of a standard, and WCAG has five of them rather than one.
• Inclusive designInclusive design means treating the full range of human variation as the starting point rather than as an edge case to accommodate once the design is finished.
• WCAGWCAG is the international standard for web accessibility, published by the W3C.