Glossary · Accessibility term
Reading level
Reading level is how much schooling a piece of text assumes, and WCAG measures it in years rather than in ages. The standard defines lower secondary education as ending nine years after primary school begins. Rule 3.1.5 asks that where text needs more reading ability than that, you also offer supplemental content, or a version that does not need more reading ability than that. Two things make it less alarming than it sounds. Proper names and titles come out of the text before anybody assesses it, and that exclusion is written into the rule itself rather than into a note. And it sits at Level AAA, so most sites have no formal obligation here. There is also a third way to satisfy it that the wording hides. Write the original clearly enough and no alternative is needed at all.
In practice
The unit is nine years of school. Not an age, and not a grade in any one country's system, because the definition comes from an international classification of education rather than from a national curriculum. W3C's own suggested way of measuring it is a qualified teacher reading the text against local education standards, which tells you how much of this is judgement rather than arithmetic.
No current W3C page names a particular formula. Not the criterion, not the glossary, not the Understanding page, and not one of the five sufficient techniques. What two of those techniques do say is measure the readability, and one of them writes a readability formula is applied straight into its worked example. So a formula is a sanctioned instrument and never the standard. The resources W3C points you at include an article arguing that formulas do not do the job plain language needs, and the reason is easy to see. A formula counts syllables and sentence lengths, and it will tell you that a page broken into short bulleted lines has long sentences.
The alternative can be more than another block of prose. Supplemental content is a defined term, and its own examples run to an audio version of the page, an illustration of a complicated process, and a paragraph summarising the outcomes. A sign language version counts too, because for some deaf readers a signed version is easier to follow than a written one, which is a route almost nobody knows exists.
Why it matters
This is the criterion W3C is most honest about. The working group could not find a way to test whether writing is clear, so it brought in reading level to make the idea testable at all, and said as much on the page. No published test rule automates it either. Which is exactly why the formula shortcut is so tempting, and exactly why a score on its own settles nothing. Level AAA means most sites owe nothing here formally. Clear writing is not therefore optional, because error messages and form instructions are Level A obligations and both have to be text somebody can act on.
What comes out before you measure
Proper names and titles are removed from the text first, and titles here means the names of documents, books and films rather than headings. So a page dense with case citations and product names is assessed on everything else, because changing those words would make the page easier to score and impossible to use.
Where this shows up on the site
Related terms
- Plain languagePlain language is writing that lets somebody find what they need, understand it the first time, and act on it.
- Easy readEasy read is a document format made for people with learning disabilities.
- Cognitive disabilityCognitive disability is a broad group of conditions affecting how people take information in, hold on to it, and act on it.
- UnderstandableUnderstandable is the third of WCAG's four principles, and it splits in two the way its own sentence does.
- Level A, AA, AAALevel A, AA and AAA are WCAG's three conformance levels, and they stack.
Knowing the word is the easy part.
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