No single font is universally “best” for dyslexia, but research consistently points to sans-serif fonts like Arial, Helvetica, and Calibri as the strongest performers for readability. These common, freely available fonts outperform most alternatives in reading speed and accuracy, and they’re already installed on virtually every device you own.
Why Sans-Serif Fonts Work Better
Sans-serif fonts lack the small decorative strokes (serifs) that appear at the ends of letters in fonts like Times New Roman or Georgia. Those extra strokes can make letters look more similar to each other, which is a core problem for dyslexic readers who already struggle to distinguish between characters like b, d, p, and q.
A study from the University of Michigan measured how long readers’ eyes paused on individual words across different fonts. Readers spent an average of 0.24 seconds per fixation with sans-serif fonts compared to 0.26 seconds with serif fonts. That difference sounds tiny, but it compounds across every word on every page. Over a full chapter or document, sans-serif fonts meaningfully reduce the effort required to read.
The British Dyslexia Association recommends a specific list of sans-serif options: Arial, Calibri, Century Gothic, Comic Sans, Open Sans, Tahoma, Trebuchet, and Verdana. When the same study ranked fonts by both reading performance and reader preference, Helvetica and Arial came out on top, with no other sans-serif or serif font consistently matching them on both measures.
What About OpenDyslexic and Other Specialized Fonts?
OpenDyslexic is a free, open-source font designed specifically for dyslexic readers. Its letters have heavier bottoms, which are meant to anchor the characters and prevent them from appearing to rotate or flip. It’s one of the most widely known dyslexia-specific fonts, and browser extensions for Chrome and Firefox can override website fonts with OpenDyslexic automatically.
A study from University College London compared OpenDyslexic to Arial with 40 dyslexic readers and 38 non-dyslexic readers (all primary school age). Participants scored significantly higher in both reading accuracy and reading speed when text was presented in OpenDyslexic. However, there was no significant difference in reading comprehension between the two fonts. So OpenDyslexic helped readers decode words more accurately and quickly, but it didn’t change how well they understood the material.
One interesting finding from that study: the researchers also tested a version of Arial with extra spacing to match OpenDyslexic’s wider default spacing. The spacing alone didn’t produce a significant improvement, suggesting that OpenDyslexic’s letter shapes, not just its generous spacing, contributed to the accuracy gains.
That said, readers’ personal font preferences didn’t consistently match their test scores. Some participants who performed better with OpenDyslexic still preferred Arial. Comfort and familiarity matter, and a font that feels strange or childish to a reader may discourage them from using it regardless of the data.
The Comic Sans Question
Comic Sans shows up on nearly every dyslexia-friendly font list, which surprises people who associate it with informal or unprofessional design. It works because its letters are relatively distinct from one another. The lowercase “a” in Comic Sans, for example, looks like a handwritten “a” rather than the more stylized version found in most fonts. That makes it harder to confuse with other characters.
But the idea that people with dyslexia can “only read Comic Sans” is a myth. Dyslexia Scotland has addressed this directly: research shows dyslexic readers can read many different typefaces and will find ones they personally prefer. Comic Sans is one good option among several, not a requirement.
Spacing and Size Matter as Much as Font Choice
The font you choose is only part of the equation. How that text is formatted on the page can have just as large an impact on readability. The Web Content Accessibility Guidelines (WCAG 2.2) set specific spacing thresholds that benefit dyslexic readers:
- Line height: at least 1.5 times the font size
- Paragraph spacing: at least 2 times the font size
- Letter spacing: at least 0.12 times the font size
- Word spacing: at least 0.16 times the font size
In practical terms, if your text is 16 pixels, paragraphs should have at least 32 pixels of space between them, and line height should be at least 24 pixels. These numbers aren’t arbitrary. Crowded text creates a phenomenon sometimes called “rivering,” where the white space between words forms distracting vertical channels that pull the eye away from the actual line of text. Generous spacing breaks up those visual patterns.
For font size, avoid anything smaller than 12 points in print or 16 pixels on screen. Larger is generally better, and the key principle for digital text is to use relative sizing (percentages or scalable units) rather than fixed pixel sizes, so readers who’ve set their browser to display larger text aren’t overridden by the website’s design.
Background Color and Visual Stress
Some dyslexic readers experience visual stress, where high-contrast black text on a pure white background creates a glare effect that makes words appear to shimmer or move. Colored overlays or tinted backgrounds can reduce this, but the specific color that helps varies from person to person. There’s no single “best” background color.
A cream or soft pastel background often works as a starting point. Schools frequently keep a set of colored overlay sheets available so students can experiment. On digital devices, most operating systems now include color filter or “reading mode” settings that warm the screen tone. Avoiding bright, strongly saturated colors in text or backgrounds also helps reduce visual distraction.
How to Choose the Right Font for You
If you’re selecting a font for your own reading, start with Arial or Calibri. They’re clean, widely available, and backed by the strongest combination of research data and expert recommendations. If those feel difficult, try OpenDyslexic, which you can install as a browser extension or download as a system font for free. Comic Sans, Verdana, and Tahoma are also solid alternatives worth testing.
If you’re designing documents, presentations, or websites for others, Arial or Calibri at 12 points or larger with 1.5 line spacing is a safe default that works well for dyslexic and non-dyslexic readers alike. Left-align your text rather than justifying it, since justified text creates uneven word spacing that can trigger the rivering effect. Keep paragraphs short and leave plenty of white space between sections.
The most important thing the research makes clear is that individual variation is real. A font that works perfectly for one dyslexic reader may not be the best choice for another. The recommendations above are strong starting points, but personal testing always beats a universal prescription.