Reading level

WCAG 3.1.5 asks that where text requires reading ability more advanced than lower secondary education, supplemental content or a simpler version is available. The plugin measures for it and gives you somewhere to put the simpler version.

How it is measured

Pages are scored against the Flesch–Kincaid grade level, which estimates the years of education a reader needs from sentence length and syllable count.

Text above roughly lower secondary level is flagged by the reading-level-high check.

What the measure can and cannot do

It counts syllables and sentence lengths. That is all it does.

It cannot tell whether your writing is clear. A page of short sentences made entirely of jargon will score well and still be impenetrable. A long, elegant sentence may score badly and read perfectly.

So treat it as a prompt to look, not a verdict. The check is marked as needing a person for exactly this reason.

Very short pages

Pages below a minimum word count are not measured, because the statistic is meaningless on a handful of words. A three-word heading will produce a wild grade level and tell you nothing.

That threshold is adjustable:

add_filter( 'wsak_readability_minimum_words', function ( int $minimum ): int {
    return 150;
} );

The plain-language summary

Where the text is genuinely heavy going, the answer WCAG wants is not to dumb the page down. It is to provide a summary alongside it.

The plugin gives each page a field for a plain-language summary so you can write one without restructuring the page. The original stays exactly as it is.

wsak_simplified_summary filters the summary, if you need to source it from somewhere else or render it differently.

Writing one that helps

Say what the page is about and what the reader should do, in short sentences and ordinary words. Three or four sentences is usually plenty.

It is not an abstract and it is not marketing copy. It is the version you would give somebody who asked you what the page said.