Short answer: Give your body text a line height of at least 1.5, keep lines to 80 characters or fewer, and don’t justify it. Then check that nothing gets cut off when a visitor increases the spacing, as W3C’s text spacing criterion asks.
What line height is
Line height sets the height of each line of text, so it controls the space between lines. In CSS it’s the line-height property. Browsers use roughly 1.2 by default, depending on the font.
MDN recommends setting it as a number without units, such as 1.5. The browser multiplies that number by the font size, so the spacing grows with the text when someone zooms in.
| Setting | What to aim for | Who asks |
|---|---|---|
| Line height | At least 1.5 times the font size for paragraphs | MDN; W3C 1.4.8, Level AAA |
| Space between paragraphs | At least 1.5 times larger than the line spacing | W3C 1.4.8, Level AAA |
| Line length | No more than 80 characters, or 40 in Chinese, Japanese and Korean | W3C 1.4.8, Level AAA |
| Alignment | Not justified | W3C 1.4.8, Level AAA |
| Visitor’s own spacing | Nothing lost with line height 1.5, paragraphs 2, letters 0.12 and words 0.16 times the font size | W3C 1.4.12, Level AA |
Based on W3C and MDN, read November 4, 2026.
How much line height and line length to use
MDN recommends a line height of at least 1.5 for main paragraph text. It helps people with low vision and people with dyslexia. Our dyslexia-friendly font guide covers what else helps them read.
W3C’s visual presentation criterion, at Level AAA, goes further. It asks for a way to get line spacing of at least space-and-a-half and paragraph spacing at least 1.5 times larger than that. It also names lines of no more than 80 characters and text that isn’t justified.
That way can be the browser or another tool, so your page doesn’t have to use those values. People with some cognitive disabilities find it hard to track text when lines sit close together, and long lines make some readers lose their place. Justified text can open rivers of white space between words.
Let visitors change the spacing
Some people set their own spacing with a browser extension or a bookmarklet. W3C’s text spacing criterion, at Level AA, says no content or function may be lost when they do. Its test values are line height at 1.5 times the font size, paragraph spacing at 2 times, letter spacing at 0.12 times and word spacing at 0.16 times.
Your page doesn’t have to use those values. It has to survive them. W3C lists clipped or overlapping text as the common failure, and an ellipsis only passes if the full text is still available. Sizing text boxes in em units, one of its techniques, lets them grow with the text.
Our website fonts guide covers choosing the typeface, and our Flesch reading ease guide covers the words themselves.
How to check the spacing of your text
- Open a page with long paragraphs and inspect one in your browser’s developer tools.
- Read its font size and line height, and set the line height to 1.5 or more as a number without units.
- Count the characters in a typical line and narrow the text column if lines run past 80.
- Let text boxes grow with their text instead of giving them a fixed height.
- Align the text to one side instead of justifying it.
- Apply W3C’s four text spacing values with a bookmarklet or a test style sheet.
- Look for cut off or overlapping text at desktop and phone widths, and fix the boxes that cause it.
Our accessibility checker guide covers the automatic tests that find other problems on the same pages.
How our own pages space their text
On November 4, 2026 we measured the body text of 10 of our guides in a browser, 5 in English and 5 in Spanish. Paragraphs use an 18-pixel font on a desktop screen and 16.5 pixels on a phone.
The line height is 1.65 in both, set as a number without units, and the text is aligned to one side. The median line holds 65 characters on a desktop screen and 40 on a phone.
W3C’s text spacing test found one problem, in our footer on phones. The left column was as wide as our email address, so with the extra spacing the right column ran past the screen and cut words such as “management”.
The same day we gave the contact column its own row and let both columns share the width. With W3C’s spacing, no footer text is cut at 360, 390, 768 or 1,440 pixels.
Before you publish your text
- Body text has a line height of 1.5 or more.
- The line height is a number without units.
- Lines stay at 80 characters or fewer.
- Text boxes grow with their text.
- The text is aligned to one side, not justified.
- Nothing is cut off with W3C’s text spacing applied.
RememberGive body text room, with a line height of at least 1.5 and lines under 80 characters. Then test that your layout survives a visitor’s own spacing.
Readable layouts are part of our web design service.
Quick answers about line spacing
What is a good line height for body text?
MDN recommends at least 1.5 for main paragraph text, which helps people with low vision and people with dyslexia. Browsers use roughly 1.2 by default, depending on the font, so set it yourself.
Are line height and line spacing the same thing?
Yes. In CSS the property is line-height, and W3C’s text spacing criterion calls it line height, or line spacing. It sets the height of each line of text, so a larger value adds space between lines.
How many characters should a line of text have?
W3C’s visual presentation criterion, at Level AAA, names a width of no more than 80 characters, or 40 for Chinese, Japanese and Korean. W3C notes that long lines make some readers lose their place.
Should I justify the text on my website?
No. W3C’s visual presentation criterion asks for text that isn’t justified. The uneven spaces between words in fully justified text can form rivers of white space that make reading difficult.
What is WCAG text spacing?
Success criterion 1.4.12, at Level AA. Its test values are line height at 1.5 times the font size, paragraph spacing at 2 times, letter spacing at 0.12 times and word spacing at 0.16 times. With those, no content or function may be lost.
Sources
Read on November 4, 2026. W3C Web Accessibility Initiative: Understanding SC 1.4.12 Text Spacing (Level AA) and Understanding SC 1.4.8 Visual Presentation (Level AAA). MDN Web Docs: line-height CSS property. Our case: our own pages, measured in a browser on November 4, 2026.