Category: WCAG Principles and Conformance

Conforming Alternate Version

Also known as: Conforming Alternative Version, Alternate Version

Simply put

A conforming alternate version is a separate, accessible version of a web page or piece of content that provides all the same information and functionality as an inaccessible version. It is one way an organization can meet accessibility requirements when the primary content cannot be made accessible directly. A text-only page can serve this role only if it fully meets the applicable accessibility requirements, not simply because it is text-based.

Formal definition

In WCAG terminology, a conforming alternate version is a version of content that conforms at the designated conformance level, provides all of the same information and functionality in the same human language, and is as up to date as the non-conforming content. According to W3C guidance, the conforming alternate version does not need to reside within the scope of conformance or even on the same website, provided it is as freely available as the non-conforming version and can be reached from it (or from an accessibility-supported mechanism). The mechanism allows authors to satisfy conformance by pointing users to an accessible alternative when the primary page relies on technologies or designs that cannot meet the success criteria. Practitioners should note that a version labeled as text-only or otherwise 'accessible' qualifies as a conforming alternate version only if it actually satisfies all applicable WCAG success criteria at the target level. The Access Board's ICT accessibility baseline and W3C both define the term, and its acceptability in legal or regulatory contexts may be limited; recent guidance has questioned reliance on conforming alternate versions, so readers should consult current agency rulemaking and qualified legal counsel. This entry is not legal advice.

Why it matters

Conforming alternate versions matter because they represent one of the sanctioned pathways in WCAG for meeting conformance when a primary page cannot be made accessible directly. For organizations working with legacy systems, complex interactive content, or technologies that cannot readily satisfy the applicable success criteria, this mechanism offers a defined way to provide equivalent access. Understanding it correctly helps teams avoid the common misconception that any separate 'text-only' or 'accessible' page automatically qualifies. Under W3C guidance, a version only serves as a conforming alternate version if it actually conforms at the designated level and delivers all of the same information and functionality in the same human language, kept as up to date as the non-conforming content.

Who it's relevant to

Accessibility Engineers and Developers

Engineers responsible for remediation should understand when a conforming alternate version is an appropriate strategy and when it is not. Because the alternate version must provide all of the same information and functionality, be in the same human language, and stay as up to date as the primary content, maintaining two synchronized versions can introduce ongoing overhead. Verifying that an alternate version actually conforms generally requires manual and assistive technology testing, not automated checks alone.

Compliance Officers

Compliance teams need to recognize that labeling a page 'text-only' or 'accessible' does not by itself make it a conforming alternate version; the version must satisfy all applicable WCAG success criteria at the target level. Recent guidance has questioned reliance on conforming alternate versions, so their acceptability in legal or regulatory contexts may be limited. This is not legal advice, and readers should consult current agency rulemaking and qualified legal counsel.

UX Designers and Content Teams

Designers should be aware that a conforming alternate version must deliver equivalent information and functionality, which affects how parallel experiences are planned and kept in sync. Because it does not need to reside on the same website but must be as freely available as the non-conforming content and reachable from it, teams should plan for discoverable, reliable navigation between versions.

Legal Counsel

Counsel evaluating accessibility strategy should note that while both the W3C and the Access Board's ICT accessibility baseline define conforming alternate versions, their acceptability in legal or regulatory contexts may be limited, and recent guidance has questioned reliance on them. Requirements evolve through regulation and case law, so decisions should be informed by current agency rulemaking. This entry is informational and not legal advice.

Inside Conforming Alternate Version

Definition (per WCAG)

A conforming alternate version is a separate version of content that, as defined by the W3C's WCAG, conforms at the desired level, provides all of the same information and functionality in the same human language, is as up to date as the non-conforming content, and can be reached from the non-conforming content (or vice versa) via an accessibility-supported mechanism.

Equivalence requirement

The alternate version must convey all of the same information and functionality as the original non-conforming content, not a reduced or partial subset.

Reachability mechanism

Users must be able to reach the conforming version from the non-conforming page through an accessibility-supported means, such as a clearly labeled and keyboard-operable link.

Currency requirement

The conforming alternate version must be kept as up to date as the primary, non-conforming version, so content parity is maintained over time.

Same-language requirement

The alternate version must be provided in the same human language as the content it replaces.

Text-only version (as one possible form)

A so-called text-only version is sometimes offered as a conforming alternate version, but it qualifies only if it actually meets all applicable WCAG requirements at the target conformance level; a stripped-down page that lacks equivalent information or functionality does not qualify.

Common questions

Answers to the questions practitioners most commonly ask about Conforming Alternate Version.

Is a separate "text-only" version of a page automatically a conforming alternate version?

No. A separate text-only page is only a conforming alternate version if it meets all WCAG conformance requirements, provides the same information and functionality as the primary page, is up to date, and can be reached from the non-conforming page (or vice versa) through an accessible mechanism. A text-only version that fails any of these conditions does not qualify. The label "text-only" describes a design approach, not conformance status.

Does providing a conforming alternate version mean the main page no longer needs to be accessible?

Not as a general strategy. Under WCAG, a conforming alternate version is intended as a fallback mechanism where the primary content cannot be made to conform, not as a substitute for making the main page accessible. Relying on a separate accessible version is often discouraged because such versions can fall out of sync, may offer a lesser experience, and may not satisfy expectations under applicable laws. Meeting WCAG conformance in the primary content is generally the preferred approach; consult qualified legal counsel regarding specific compliance obligations.

How can users find the conforming alternate version from a non-conforming page?

WCAG generally requires that the conforming alternate version be reachable through an accessible, conforming mechanism. This commonly means a link that is itself accessible and clearly identifies the alternate version, or an automated redirect based on user settings or content negotiation. The pathway between the versions should not itself rely on inaccessible content, or users may be unable to reach the conforming version.

Does the alternate version have to contain exactly the same information as the primary page?

It must provide the same information and functionality. The alternate version should not omit content or features available in the primary page, and it must be kept up to date as the primary content changes. Differences in presentation are acceptable, but reductions in available information or functionality generally disqualify it from being a conforming alternate version.

What are the practical maintenance challenges of using a conforming alternate version?

The main challenge is keeping the alternate version synchronized with the primary content. Any update to information or functionality on the primary page must be reflected in the alternate version, or the alternate may no longer conform. This creates ongoing overhead and a risk of drift, which is a common reason accessibility practitioners recommend making the primary content conform rather than maintaining parallel versions.

How should a conforming alternate version be tested?

The alternate version should be evaluated against the full set of applicable WCAG success criteria at the target conformance level, just as any conforming page would be. This generally requires a combination of automated checks, manual review, and testing with assistive technologies, since automated tools detect only a portion of potential issues. Testing should also confirm that the linking or redirection mechanism between versions is accessible and that content parity is maintained.

Common misconceptions

A conforming alternate version lets you leave the main page inaccessible indefinitely.

The concept is generally treated as a fallback rather than a preferred approach. Making the primary content directly accessible is commonly recommended; an alternate version still must be equivalent, reachable, and kept as current as the main content, which is often difficult to maintain.

Any separate 'text-only' or simplified page automatically counts as a conforming alternate version.

A separate version only qualifies if it meets all WCAG conformance requirements at the target level and provides the same information and functionality. A simplified page that omits content or functionality, or that itself fails success criteria, does not satisfy the definition.

Providing a conforming alternate version guarantees legal compliance or immunity from claims.

Meeting the WCAG definition of a conforming alternate version addresses a technical standard, not legal outcomes. It does not by itself guarantee compliance with the ADA, Section 508, or other authorities, and it does not ensure an equally usable experience for all users. Consult qualified legal counsel regarding specific obligations.

Best practices

Prioritize making the primary content directly accessible, and treat a conforming alternate version as a fallback rather than a default strategy.

If you provide an alternate version, ensure it delivers all of the same information and functionality in the same human language as the original content.

Provide a clearly labeled, keyboard-operable, and accessibility-supported mechanism to reach the conforming version from the non-conforming content.

Establish a maintenance process so the alternate version stays as up to date as the primary version whenever content changes.

Verify the alternate version actually meets your target WCAG conformance level (commonly AA) using both automated and manual testing, since automated tools detect only a portion of issues.

Do not rely on a conforming alternate version as assurance of legal compliance; document your accessibility approach and seek qualified legal counsel on applicable requirements.