Pick a plain font.Then give it room.
There is no proven best dyslexia friendly font. Studies of the special dyslexia fonts, OpenDyslexic and Dyslexie, found that children with dyslexia read them no faster or more accurately than Arial. What the evidence and the British Dyslexia Association point to instead is a plain sans-serif such as Arial, Verdana or Calibri at 16 to 19 pixels, with line height 1.5, a little extra space between letters and words, lines of 60 to 70 characters and left-aligned text. Better still, let each visitor switch to the font they read best in. Below: the research, the BDA’s rules, the usual fonts, a tester that writes the CSS, and how to offer a choice.
By the Builderify team
Every controlled study of a special dyslexia font that we found came out the same way: no faster or more accurate reading than with Arial. That covers OpenDyslexic, the free one, and Dyslexie, a paid font by the Dutch designer Christian Boer. The one study that saw Dyslexie win traced the gain to its wider spacing, not its letter shapes. Spacing and size, on the other hand, have measurable effects.
The studies are small, mostly with children, and in English, Dutch, Italian and Spanish. They measure speed and accuracy, not comfort or how long someone keeps reading. And readers disagree: some people with dyslexia like OpenDyslexic a lot. That is the case for offering it as a choice, not for making it everyone’s default. This page is about type on websites; it isn’t medical or educational advice.
| Study | What was tested | Readers | What they found |
|---|---|---|---|
| Zorzi et al., 2012 PNAS 109(28) Read it | Extra-large letter and word spacing, in an ordinary serif font | 74 children with dyslexia, aged 8 to 14, in Italy and France | Wider spacing “substantially improved text reading” on the spot. The authors link it to crowding: letters packed close together interfere with each other more for readers with dyslexia. |
| Rello and Baeza-Yates, 2013 ASSETS ’13, ACM Read it | 12 fonts, OpenDyslexic among them, with eye tracking | 48 people with dyslexia | Sans-serif, monospaced and upright fonts did better than serif, proportional and italic ones. OpenDyslexic did no better than ordinary fonts, and readers preferred Verdana and Helvetica to it. |
| Rello, Pielot, Marcos and Carlini, 2013 W4A ’13, ACM Read it | Six text sizes and four line spacings on Wikipedia articles | 28 people with dyslexia | The title gives it away: “Size matters (spacing not)”. Reading improved as text grew to 18 points; line spacing made no significant difference. |
| Marinus et al., 2016 Dyslexia 22(3) Read it | Dyslexie against Arial, then against Arial spaced like Dyslexie | Children who were behind in reading | They read about 7% more words a minute in Dyslexie than in standard Arial, but the difference was no longer significant once Arial had the same letter and word spacing. |
| Wery and Diliberto, 2017 Annals of Dyslexia 67(2) Read it | OpenDyslexic against Arial and Times New Roman | 12 students with dyslexia, aged about 9 to 12 | No font made reading faster or more accurate. The authors: “there may be no benefit for translating print materials to this font.” A small sample, as they say themselves. |
| Kuster et al., 2018 Annals of Dyslexia 68(1) Read it | Dyslexie against Arial and Times New Roman | 170 children with dyslexia; then 102 with and 45 without | Dyslexie neither helped nor hindered. Most children preferred Arial, and which font they preferred had nothing to do with how well they read in it. |
Weighted bottoms and exaggerated letters didn’t make children read faster or more accurately than a plain sans-serif.
Wider letter spacing helped in Zorzi’s study and explained Dyslexie’s edge in Marinus’s. Bigger text helped up to about 18 points.
Which font children preferred had nothing to do with how well they read in it. So set sensible defaults and let people change them.
The BDA’s Dyslexia Style Guide (2023 edition) asks for a plain sans-serif at 16 to 19 pixels, line spacing of 1.5, slightly wider letter spacing, lines of 60 to 70 characters, left-aligned text, bold for emphasis and an off-white background.BDA It was written for documents as much as screens, so the right-hand column turns each point into a CSS property. The BDA also says to use its guide alongside WCAG, not instead of it.
font-family: Arial, Verdana, sans-serif;font-size: 1.125rem; /* 18px */letter-spacing: 0.12em;word-spacing: 0.16em;line-height: 1.5;max-width: 65ch;text-align: left;font-weight: 700; /* not italic, not uppercase */h2 { font-size: 1.5em; }background: #fbf7e9;The pixel figures are the guide’s own conversion of 12 to 14 point. Its letter spacing is a share of the letter width, which CSS can’t express directly, so the column uses WCAG’s 0.12em test value instead (chapter 05). For text size and colour contrast on their own, the WCAG 2.2 checklist covers resizing text (1.4.4) and contrast (1.4.3) in plain English.
For a website, Arial or Verdana is the safe default: both are on the BDA’s list and on almost every computer, so nothing has to download. Open Sans, Lexend and Atkinson Hyperlegible Next are free web fonts to load if you want something with more character. OpenDyslexic is best offered as a switch, not as your only font. None of these makes up for cramped spacing.
Monotype, for Windows and macOS
The BDA’s first suggestion, and the font most children chose over Dyslexie in Kuster et al. On most Windows and Apple devices; Android draws a look-alike instead.
Matthew Carter, for Microsoft
Wide letters and generous spacing, drawn for screens. On Windows and macOS. Readers in Rello and Baeza-Yates preferred it to OpenDyslexic.
Matthew Carter, for Microsoft
A narrower cousin of Verdana. On the BDA’s list. Ships with Windows and macOS.
Microsoft
Soft, rounded and compact; long the default in Microsoft Office. On the BDA’s list. Present where Windows or Office is installed, rarely on phones.
Monotype
Round, geometric letters with a lot of space inside them. On the BDA’s list. Mostly installed with Microsoft Office, so many visitors won’t have it.
Steve Matteson, for Google
A plain, open web font, and the one web font on the BDA’s list. Free under the SIL Open Font License; you have to load it on your site.
Bonnie Shaver-Troup and Thomas Jockin
Built around wider letter and character spacing. Its makers report faster reading in their own study of 20 children; it has no independent dyslexia trial that this page could find.
Braille Institute, 2025
Drawn so that look-alike letters (I, l, 1; O, 0; b, d, p, q) stay distinct, for readers with low vision rather than dyslexia. This page is set in it.
Abbie Gonzalez
Heavy-bottomed letters designed against common reading problems in dyslexia. Free under the SIL Open Font License. Studies so far found no reading gain over Arial, but some readers prefer it.
Also on the BDA’s list: Trebuchet MS and Comic Sans, both installed on Windows and macOS and both in the tester below. Sources for the newer fonts: the Braille Institute’s release of Atkinson Hyperlegible NextBraille Inst., Lexend’s own siteLexend and OpenDyslexic’sOpenDyslexic.
Paste a paragraph from your site, pick a font and move the sliders. The preview changes as you go, the checklist marks each setting against the BDA guide and the WCAG text spacing values, and the CSS underneath is ready to copy. It starts as a typical small-business page, justified and tightly set. Nothing you type leaves your browser.
2 pass · 1 to check · 7 fail
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Some letters are easy to mix up: b and d, p and q, I, l and 1, rn and m. A clear font with room around each letter keeps them apart.
Checklist
Typeface Arial BDA
A plain sans-serif named in the BDA guide.
Text size 15px (0.9375rem) BDA
Under the BDA’s 16 to 19px.
Line height 1.3 BDA · WCAG 1.4.12
Under 1.5.
Letter spacing 0em WCAG 1.4.12
Under 0.12em.
Word spacing 0em WCAG 1.4.12
Under 0.16em.
Paragraph spacing 1em WCAG 1.4.12
Under 2em.
Line length 95ch BDA · WCAG 1.4.8
Over the 80 characters of WCAG 1.4.8.
Alignment Justified BDA · WCAG 1.4.8
Justified text leaves uneven gaps between words.
Italics and capitals Normal BDA
Upright, in lower and upper case.
Background White BDA
The BDA suggests an off-white, such as cream or a soft pastel.
Your CSS
/* Body text: BDA Dyslexia Style Guide 2023 and WCAG 2.2 SC 1.4.12 */
body {
font-family: Arial, Helvetica, sans-serif;
font-size: 0.9375rem; /* 15px */
line-height: 1.3;
letter-spacing: normal;
word-spacing: normal;
color: #222222;
background: #ffffff;
}
p {
max-width: 95ch;
margin: 0 0 1em;
text-align: justify;
}
Scope it to your content area (for example main or .post) rather than body if your theme sets its own sizes.
Fonts you don’t see. This page loads only Atkinson Hyperlegible Next. The rest are drawn from your own device, so if one isn’t installed the tester says so and shows the fallback rather than pretending.
What “pass” means. The WCAG rows check your settings against the 1.4.12 test values. The criterion itself asks that your page still works when a visitor applies them; chapter 05 explains.
Characters, not ch. One ch is the width of a zero. Most letters are narrower, but letter spacing widens every one, so how many characters fit in 65ch depends on the font and the spacing; in Arial it is roughly 60 to 70. The count above the preview shows roughly how many fit.
Set the font size in rem, line height 1.5, a little letter and word spacing, a maximum line length in ch and left alignment. That covers most of the BDA guide and leaves room for the visitor’s own settings.
Size in rem, not px. 1.125rem is 18px by default but grows when a reader raises the text size in their browser settings. Pixel sizes ignore that setting.
Spacing as units of the text. Unitless line-height and spacing in em scale with the font, so they stay right at every size.
A maximum, not a fixed width. max-width: 65ch on paragraphs keeps lines short on a wide screen and lets them wrap on a phone.
No fixed heights on text boxes. Buttons, cards and menus with a set height clip their text the moment someone adds spacing. Let them grow.
Emphasis in bold. Keep italics for titles of works and keep capitals for short labels, not sentences.
/* Body text: BDA Dyslexia Style Guide 2023 and WCAG 2.2 SC 1.4.12 */
body {
font-family: Arial, Helvetica, sans-serif;
font-size: 1.125rem; /* 18px */
line-height: 1.5;
letter-spacing: 0.12em;
word-spacing: 0.16em;
color: #222222;
background: #fbf7e9;
}
p {
max-width: 65ch;
margin: 0 0 2em;
text-align: left;
}
The tester’s “Apply BDA + WCAG values” output
SC 1.4.12 Text Spacing (level AA) doesn’t tell you which spacing to use. It says that when a visitor sets line height to 1.5 times the font size, paragraph spacing to 2 times, letter spacing to 0.12 times and word spacing to 0.16 times, no content or function may be lost.W3C Using those values as your own defaults is a simple way to know your layout survives them.
SC 1.4.8 Visual Presentation (level AAA) goes further for blocks of text: lines no wider than 80 characters, no justified text, line spacing of at least one and a half, and a way for visitors to choose text and background colours.W3C AAA is rarely required, but these points match the BDA closely.
Since no single font suits every reader, the most useful thing after good defaults is a way to change them. There are three: the reader mode in the visitor’s own browser, an accessibility toolbar on your site, or a switch you build yourself.
Free, already there
Most browsers can strip a page to its text and let the reader set the font, size and spacing. It only works well on pages built from real headings and paragraphs, so clean markup is your part of the deal. Visitors have to know it exists.
On your site
A button on every page that opens display options: a dyslexia font, bigger text, more spacing, contrast. Visitors don’t need to know a browser feature. It changes how the page looks, not how it’s built.
Do it yourself
A button that adds a class to the page, a stylesheet that swaps the font family under that class, and a saved preference. Self-host OpenDyslexic so it loads only for people who ask, and test the layout with the wider letters.
In Builderify
Builderify’s accessibility widget is a toolbar of 13 adjustments that each visitor controls, and you choose which ones to offer. Its Dyslexia Friendly tool switches the page’s text to OpenDyslexic, in regular and bold, with Verdana shown until the font arrives. The font files travel with the Builderify script itself and are only fetched when someone turns the tool on, so visitors who don’t use it download nothing extra and no third-party font service is called. Icons are left alone.
Next to it: Text Spacing, which opens up line height, letter spacing and word spacing; a Font Size slider from 50% to 200%, which scales the page’s root size, so text set in rem follows and text fixed in pixels doesn’t (one more reason for tip 1 above); contrast modes; and a reading guide that follows the cursor. A visitor’s choices stay with them as they move from page to page. It all ships in the same script as the website widget and the other modules, added once to your site’s head.
A toolbar changes how a page looks for one visitor. It doesn’t fix your own fonts, spacing, headings or contrast, and it doesn’t make a site ADA or WCAG compliant; Builderify doesn’t claim it does. Read why accessibility overlays aren’t compliance before relying on any toolbar, and on WordPress, what an accessibility plugin can and can’t fix.
Mentioning the toolbar in your accessibility statement? Describe it as extra help. Selling to customers in the EU? Check whether the European Accessibility Act applies to your business.
Every account gets 250 free credits a month; page loads with the widget on them cost 10 credits per 1,000. There is no monthly fee, packs start at $9 and purchased credits never expire. See the pricing page.
For a document, use Arial, Verdana or another plain sans-serif at 12 to 14 point, line spacing 1.5, left-aligned, with bold headings and no blocks of italics or capitals. Those are the BDA’s figures, written with print in mind. Word, Google Docs and Canva all let you set the font, size, line spacing and alignment; check that whoever opens the file has the same font, or export a PDF. A flyer image with text baked in can’t be resized or read aloud, so put the words on your web page too.
No single font has been shown to be best. The British Dyslexia Association suggests a plain sans-serif such as Arial or Comic Sans, with Verdana, Tahoma, Century Gothic, Trebuchet, Calibri and Open Sans as alternatives. Size and spacing matter as much as the font: 16 to 19 pixels, line spacing of 1.5 and lines of 60 to 70 characters.
Not in the studies so far. Wery and Diliberto (Annals of Dyslexia, 2017) found children with dyslexia read OpenDyslexic no faster or more accurately than Arial or Times New Roman, and Rello and Baeza-Yates (2013) found it did no better than ordinary fonts. Some readers still prefer it, which is why it works best as an option they can switch on.
The BDA style guide gives 12 to 14 point, which it equates to 16 to 19 pixels, and some readers want larger. Set it in rem, for example 1.125rem for 18px, so it still grows when a visitor raises the text size in their browser.
No. A toolbar lets each visitor change how the page looks, but it does not fix your own fonts, spacing, headings or contrast, and it does not make a site ADA or WCAG compliant. Builderify does not claim its accessibility widget does; treat it as extra help on top of a well-built page.
OpenDyslexic, a free font under the SIL Open Font License, in regular and bold, with Verdana shown until it loads. The font is only downloaded when a visitor switches the tool on, and the visitor can switch it off again at any time.
All read on 30 October 2026. The BDA’s site refused a direct download of its 2023 guide that day, so its wording was checked through search excerpts of the PDF and pages quoting it. Study findings are summarised from each paper’s abstract or full text; read the papers for their methods and limits. The Builderify details come from the Accessibility module and the rate card on this site. Nothing here is medical, educational or legal advice.
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