WCAG 2.2 · Guideline 3.1 · Understandable
Readable
The page has to say what language it is in, and mark where that changes.
Before a screen reader can pronounce a page it has to be told what language the page is in. Feed French words to an English voice and you get noise. That is the whole of what this guideline asks at Level A and AA, which catches people out, because the name promises plain writing. Reading level, unusual words, abbreviations and pronunciation are all here too. All four of them sit at Level AAA.
Two A/AA success criteria live here, out of six, so two thirds of this guideline sits above the level almost every law names. The two that get audited are small and cheap. Declare the page language in the code, then mark any passage that switches out of it, and a site published in one language has already satisfied the second rule by satisfying the first. Nothing under 3.1 has changed since WCAG 2.0 in 2008, which makes it one of only three guidelines an old audit still covers exactly as a new one would. And 3.1 is a goal rather than a rule, so a report naming it is naming 3.1.1 or 3.1.2.
- Rules
- 2
- Level A
- 1
- Level AA
- 1
- Human testing only
- 0
All 2 Readable rules
- 3.1.1Level ALanguage of PageEvery page has to declare its main language in a way software can read, and on the web that means one attribute on the html element.Scanner-detectable4 fixes
- 3.1.2Level AALanguage of PartsWhen a passage switches language, that passage needs its own lang attribute, so the screen reader switches pronunciation for it and switches back afterwards.Partly scannable2 fixes
Level AAA in this guideline
4 enhanced criteria sit under 3.1. They are outside the level almost every law names, so our audits treat them as reference rather than scope. Some are still worth adopting, and the Level AAA hub says which.
- 3.1.3Level AAAUnusual WordsWhere a word or phrase is used in an unusual or restricted way, the reader needs a way to find the definition you meant.Not graded7 fixes
- 3.1.4Level AAAAbbreviationsEvery abbreviation needs its expanded form or its meaning available to the reader.Not graded7 fixes
- 3.1.5Level AAAReading LevelWhere your text needs more reading ability than lower secondary education, you owe the reader either supplemental content or a simpler version.Not graded5 fixes
- 3.1.6Level AAAPronunciationWhere a word's meaning is ambiguous unless you know how it is said, the reader needs a way to find the pronunciation.Not graded5 fixes
What goes wrong here
These are the failures we find repeatedly under 3.1, across sites of every size.
- The html element has no lang attribute, or the wrong one. A screen reader then applies the wrong pronunciation rules, and how bad that gets depends on the language pair and the software.
- A passage in another language has no lang of its own. Proper names, technical terms, words of indeterminate language and phrases that have entered the surrounding language are all excepted, so this is narrower than it first sounds.
- Specialist terms and abbreviations appear with nothing anywhere on the page that gives their meaning. This is a Level AAA obligation, and a glossary link or a definition list satisfies it as well as an inline expansion does.
- The writing runs well past what the audience can follow, in legal and medical copy above all.
Who it affects
- Screen reader users, whose software uses the declared language to choose how to speak the text.
- People with cognitive and learning disabilities, for whom dense sentences and unexplained jargon close the content down entirely.
- People reading in a second language, who need the terms defined rather than assumed.
- Translation tools, which use the declared language as one signal. Search engines are a separate question, and at least one major engine works the language out from the text and does not read the attribute at all.
How to work through it
- 1Check the html element declares the right language, then check the passages. Read the inherited value in the code rather than trusting what you hear, because an accessible name assembled from several sources can lose a language change that the markup got right.
- 2Collect the abbreviations and specialist terms and ask whether a mechanism exists for finding either the expanded form or the meaning. This is Level AAA, so treat what it turns up as a stretch goal rather than an audit finding.
- 3Read the page aloud and mark every sentence you have to restart. That is the reading-level check that actually works, and the criterion behind it measures against lower secondary education level once proper names and titles are removed.
- 4For content that has to stay technical, add a plain-language summary alongside it. Supplemental content is an accepted alternative to rewriting, which matters when the precision is the point.
How the levels build
Level A asks for one thing: the page declares its language. Level AA adds the language of individual passages, with its four exceptions. Level AAA adds four more, and they are the reason this guideline looks bigger than it is. Definitions for unusual words, the expanded form or meaning of abbreviations, a simpler version or supplemental content where the writing runs past lower secondary level, and pronunciation where meaning depends on it. That last one is about words whose meaning changes with how they are said. There is no pronunciation requirement for abbreviations anywhere in the standard, which is a rule people invent and then audit against.
Other Understandable guidelines
- 3.2PredictableThe interface has to behave the same way twice, and never change on its own.
- 3.3Input AssistanceForms have to help people avoid mistakes and recover from the ones they make.
Part of the Understandable principle · browse by level: Level A · Level AA · or the full 55-rule library.
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