Align text to one side only
Justified text is stretched to reach both margins. The stretching happens in the spaces between words, differently on every line. G169 says do not do it. Align to one side, which in left-to-right languages means left, and let the right edge stay ragged so word spacing stays even. W3C lists this as a sufficient technique for 1.4.8 Visual Presentation, a Level AAA rule that is also where line length, line spacing and user-selectable colors live. It is not a technique for the Level AA text spacing rule, which asks something different, namely that a page survive when the reader increases spacing themselves. Both are about spacing and they point in opposite directions. W3C also records fully justified text as a documented failure of that same AAA rule, so this is a case where doing the wrong thing has its own entry.
How we find it in an audit
This one is easy to catch. A CSS scan finds text-align justify wherever it is declared. Our reviewers then look at the templates carrying long-form reading, since that is where the harm concentrates. Article bodies, policy pages and printed-style documents are the usual sources, often inherited from a print stylesheet nobody revisited.
How affected users experience it
For readers with dyslexia the uneven gaps join up into rivers of white running down the page, and the word shapes their reading leans on get distorted by the stretching. Low-vision readers at high magnification get lines whose rhythm changes on every row, which is exactly what makes losing your place easy. Ragged-right text keeps the spacing constant and takes the problem away.
Passes vs. fails
Passes
Body text is aligned left only, keeping the space between words even on every line.
Fails
A news site justifies every article to both margins, and word spacing stretches into rivers of white running through the text.
Other ways to satisfy this rule
21 guides on this site are filed under 1.4.8 Visual Presentation. W3C lists this one as sufficient for that rule on its own. Implement it correctly, in a way your readers' software actually supports, and the rule is met.
- C12sufficientSize text in percent so it scales
- C13sufficientUse named font sizes that respect user defaults
- C14sufficientSize text in em units, not pixels
- C19sufficientAlign text left or right, never justified
- C20sufficientCap line length with relative column widths
- C21sufficientGive paragraphs breathing room with line spacing
This guide is our interpretation of W3C technique G169: Aligning text on only one side. W3C publishes its techniques as guidance rather than as the standard, and says so on every one of them. The success criterion is what conformance is measured against, and a technique is one documented way to meet it.