Dyslexia-Friendly Style Guide: Fonts, Spacing, Color and Plain Language

Dyslexia is a learning disability that makes reading and spelling words harder, slower or both, even with good teaching.¹ Formatting can’t change that, but it can stop a document from adding extra work. The same choices help readers who are tired, reading in a second language or reading on a phone.^{2, 3}

If you only have two minutes, do these twelve things. Each one is explained, with its evidence, further down the page.

Paste your own text, then change the font, size, spacing, line length and background to see the difference. The tool also checks color contrast and flags long sentences. Nothing you type leaves your browser.

Pick a plain sans serif, in roman style

The British Dyslexia Association’s style guide recommended sans serif fonts such as Arial and Comic Sans, with Verdana, Tahoma, Century Gothic, Trebuchet, Calibri and Open Sans as alternatives, because the letters can look less crowded.²

The best-known test of this is an eye-tracking study by Luz Rello and Ricardo Baeza-Yates. Forty-eight people with dyslexia read texts in twelve fonts. Sans serif, monospaced and roman (upright) fonts were read more easily than serif, proportional and italic ones, and Helvetica, Courier, Arial and Verdana did best.^{12, 4} It’s one study with a small group, so read it as “choose a clear, familiar font,” not “Verdana or nothing.”

Special “dyslexia fonts” haven’t shown a benefit

Fonts designed for dyslexia have been tested several times. In a study of elementary students with dyslexia, OpenDyslexic didn’t improve reading speed or accuracy compared with Arial or Times New Roman, and none of the students preferred it.¹³ In two experiments with 170 and 102 children with dyslexia, the Dyslexie font didn’t make reading faster or more accurate, and most children preferred Arial.¹⁴ A 2020 study found no effect from the special letter shapes at all.¹⁵

So there’s no need to buy or install one. If a reader likes a particular font, though, let them use it. That’s one more reason to share files they can change.

Size, emphasis and capitals

• Size: 12–14 point for printed body text, or about 16–19 pixels on screen. Some readers will ask for bigger.²
• Headings: at least 20% bigger than body text, and bold if you need more weight.²
• Emphasis: use bold. Underlining and italics can make words seem to run together.² The UK Home Office’s accessibility posters also say not to underline words, use italics or write in capitals.⁵
• Capitals: don’t set whole sentences or paragraphs in capitals; lower case is easier to read.²
• Links: make them look different from headings and normal text.²

Spacing is where the research is most encouraging, and also where “more” stops helping if you overdo it.

Letter and word spacing

In a study of Italian and French children with dyslexia, extra-large letter spacing substantially improved their text reading, straight away and with no training. The authors link this to “crowding,” where letters packed close together are harder to recognize.¹⁶ A later study added a caution: wider letter spacing slowed reading when word spacing wasn’t increased to match.¹⁵ The BDA guide gave the same rule of thumb, letter spacing of about 35% of the average letter width and word spacing at least 3.5 times the letter spacing.²

In practice: leave the default spacing in most documents, but make sure your layout still works when a reader turns spacing up. WCAG’s text-spacing test checks this with letter spacing of 0.12 times the font size, word spacing of 0.16, line height of 1.5 and paragraph spacing of 2.¹⁷ The preview tool above has a button for it.

Lines and paragraphs

Justified text is a problem because it stretches the gaps between words unevenly, which can create “rivers” of white space running down the page.⁶ Left-aligned text keeps word spacing even and makes the start and end of each line easier to find.²

Structure

• Break long documents into sections with clear headings, and add a table of contents.²
• Use bullet points or numbered steps instead of long blocks of prose where you can.^{2, 5}
• Leave white space around text and group related things together.^{2, 3}
• Use images, diagrams and flow charts to support the words, especially for step-by-step processes.^{2, 5}

• Plain backgrounds. Use a single background color, with no patterns or pictures behind text.²
• Dark text on a light background. The BDA suggested a light background that isn’t pure white, such as cream or a soft pastel, because white can look too bright; some readers will have their own preferred color.²
• Enough contrast. For web text, WCAG asks for a contrast ratio of at least 4.5:1 for body text and 3:1 for large text.⁸ Mid-gray text on a cream background often fails, so check it.
• Don’t rely on color alone to carry meaning (“the items in red are due”). Add a word, symbol or pattern too.¹⁸ The BDA also suggested avoiding green and red/pink combinations, which are hard for people with color vision deficiency.²
• Print on matte paper thick enough that the other side doesn’t show through.²

What the research says about background colors

In a screen-reading study of 341 people, 89 of them with dyslexia, warm backgrounds (peach, orange and yellow) gave significantly better reading performance than cool ones (blue, blue-gray and green), measured mainly by reading time. People with and without dyslexia both benefited.¹⁹ That’s a reason to offer a tinted background, not a reason to force one color on everyone. Preferences differ.

Formatting makes text easier to see. Plain language makes it easier to understand, and it helps far more readers than any font choice.

The BDA guide, the W3C’s guidance on cognitive and learning disabilities, and the U.S. government’s plain language guides agree on most of the basics:^{2, 3, 9}

The Plain-Language Rewrite Sheet turns these steps into a one-page routine with a table of common word swaps.

Good formatting only helps if it survives in the file people actually receive, and if readers can change it.

All formats

• Build structure with styles. Use the heading and list tools in Word or Google Docs instead of making text bigger or bolder by hand. Assistive technology reads the structure, not the look.^{7, 2}
• Keep text as text. Don’t put paragraphs inside images, where they can’t be resized, recolored or read aloud.²¹
• Offer an editable version. A Word file or web page lets readers switch to their own font, size and background. A PDF on its own often doesn’t.²
• Think about other formats, such as audio or video, for important information.⁵
• Make it work with text-to-speech. The BDA guide was written partly so that text-to-speech tools could read documents smoothly.² Clean headings, real lists and alt text on images all help.

Slides

• Fewer words per slide, in a large sans serif font, left-aligned.
• A plain background behind text; no photos under words.²
• Share the slides before the session so people can read them at their own pace.

Web pages and email

• Let readers resize and restyle text: don’t lock font sizes or block zoom.⁶
• Make sure the page still works with WCAG’s text-spacing settings.¹⁷
• Write link text that makes sense on its own.¹⁰
• Let users change the contrast between background and text.^{5, 6}

Before you send or print, run through the Dyslexia-Friendly Document Checklist.

Formatting supports reading; it doesn’t treat dyslexia. Reading difficulties respond to structured, explicit teaching of decoding, fluency, vocabulary and comprehension.²⁰ If you’re worried about a child’s reading, talk to their school about an evaluation.

Three one-page sheets, free to copy and adapt under CC BY 4.0. Put the checklist in a staff handbook, use the rewrite sheet in a writing workshop, or give the preferences card to students at the start of term.