Alternative version
An alternative version is content offered in a different format than the original to convey the same information in an accessible way. A scanned PDF replaced by an HTML document, a complex chart accompanied by a data table, a video dubbed with a transcript: each alternative version must be complete, up-to-date, and reachable.
A 40-page PDF sent to users, except it's scanned: no text layer, no tags, nothing that a screen reader can use. The solution: offer an alternative version. The same content, in a format that everyone can access.
#Not a summary, not a byproduct
The RGAA and WCAG require three things from an alternative version:
- Same information. A quarterly sales chart cannot be reduced to "sales increased." The figures, trends, and comparisons must be there.
- Same functionality. If the original allows filtering data, so does the alternative.
- Same freshness. The original changes? The alternative keeps pace.
Some concrete examples:
| Original content | Alternative version |
|---|---|
| Scanned PDF (image) | Structured HTML document or tagged PDF |
| Interactive chart | Data table with the same values |
| Video without captions | Complete text transcript |
| Complex JavaScript animation | Accessible HTML page with the same functionality |
#Alternative version and accessible version: what's the difference?
The two terms sound similar but don't cover the same scope. The accessible version refers to an entire web page, compliant with WCAG, offered as a replacement for a non-compliant page. This is the concept of "conforming alternate version" from the W3C.
The alternative version is broader. It applies to individual content: an image, a document, a media item, a component. Providing a text transcript for a podcast is delivering an alternative version of the media. Offering an entire page without JavaScript to replace an inaccessible site is providing an accessible version.
#The classic mistake: the unfindable alternative
The alternative content exists, but no one can find it. The link is in the footer, with a label like "click here." Or the link is not keyboard accessible.
The W3C G136 technique recommends placing the link to the alternative version at the top of the page, with a clear label. An inaccessible path to accessible content helps no one.
#In summary
An alternative version offers the same information in a format that assistive technologies can use. It covers documents, media, and components — not just entire pages. And it does not replace fixing the original: it precedes it.