A dyslexic font is a typeface specifically designed to make reading easier for people with dyslexia, typically by altering letter shapes, weight, and spacing to reduce common reading errors like flipping or swapping similar-looking characters. The two most well-known examples are Dyslexie and OpenDyslexic. While these fonts are widely available and popular, research consistently shows they don’t improve reading speed or accuracy compared to standard fonts like Arial. What does help is something simpler: increased spacing between letters and words.
How Dyslexic Fonts Are Designed
People with dyslexia often confuse letters that look like mirror images of each other, such as b and d, or p and q. Dyslexic fonts try to solve this by making each letter visually distinct. The most common technique is adding extra weight to the bottom of letters, so they appear to have a heavier base. This is meant to “anchor” each character and prevent the reader’s brain from mentally rotating it.
Beyond weighted bottoms, these fonts also adjust several other typographic features. Letters are shaped so that similar characters (like b, d, p, and q) each look noticeably different from one another rather than appearing as rotations of the same form. The spacing between letters and between words is typically wider than in standard fonts. Letter height, the size of lowercase letters relative to capitals, and the overall proportions are all tweaked to maximize legibility.
Dyslexie vs. OpenDyslexic
Dyslexie was created by Dutch designer Christian Boer and is available through a paid license for commercial use, though free for personal use. It focuses heavily on altering the bottom weight of each letter and adjusting spacing. OpenDyslexic, created by Abelardo Gonzalez, takes a similar approach but is completely open-source and free. OpenDyslexic is built into many Amazon Kindle devices and can be installed as a browser extension or system font on most computers and phones.
Both fonts share the same core philosophy: make each letter harder to confuse with another. In practice, they look quite different from each other, but neither has demonstrated a clear advantage in controlled studies.
What the Research Actually Shows
This is where things get uncomfortable for fans of dyslexic fonts. Multiple studies have found no measurable benefit to reading speed or accuracy when using these specialized typefaces.
A large study of 170 children with dyslexia, published in the Annals of Dyslexia, compared reading performance in Dyslexie versus Arial. Reading speed and error rates were essentially identical between the two fonts. Children read about 93 seconds on their first passage and about 80 seconds on their second, regardless of which font they saw. The slight improvement on the second reading was a simple practice effect, not a font effect.
The results for OpenDyslexic were even worse. A separate study found that students reading in OpenDyslexic actually performed worse than when reading in Arial or Times New Roman on every measure tested, including letter naming, word reading, and nonsense word reading. On word reading fluency, students scored nearly 89% lower with OpenDyslexic compared to Arial. Accuracy dropped significantly too, with negative effects ranging from about 54% to 76% across different reading tasks. These aren’t subtle differences.
One earlier study did find a small advantage for Dyslexie (about 7% more words read per minute), but when researchers controlled for spacing, matching Dyslexie’s wider letter and word gaps in the comparison font, the benefit disappeared entirely. That finding points to an important conclusion: it’s the spacing doing the work, not the letter shapes.
Why Spacing Matters More Than Letter Shape
People with dyslexia are more susceptible to a visual phenomenon called crowding, where nearby letters interfere with each other and become harder to identify. When letters are packed closely together, the brain struggles to isolate individual characters. Increasing the space between them reduces this interference.
A landmark 2012 study showed that enlarging letter spacing by about 18% of the font’s body size significantly improved reading in children with dyslexia. In standard fonts like Times New Roman or Arial, the space between two lowercase letters varies from roughly 0 to 15% of the body size, and the space between words sits around 20 to 25%. Fonts designed with dyslexia in mind tend to push letter spacing to 16 to 18% and word spacing up to about 39% of the body size.
The British Dyslexia Association recommends a minimum text size of 14 point with generous line spacing (around 22 point), and left-justified text so the gaps between words stay consistent rather than stretching unpredictably across the line.
Standard Fonts That Work Well
If specialized dyslexia fonts don’t outperform regular ones, which regular fonts are best? Researchers at the University of Michigan’s Dyslexia Help center recommend Helvetica, Courier, Arial, Verdana, and Computer Modern as the most readable options for people with dyslexia. These are all clean, widely available fonts with distinct letterforms and good default spacing.
The common thread is simplicity. Sans-serif fonts (those without the small decorative strokes at the ends of letters) tend to perform well, though Courier, a monospaced serif font, also makes the list because every letter occupies the same width, which naturally increases spacing between narrower characters. Comic Sans, despite its reputation as a design joke, is also frequently cited as readable for people with dyslexia for similar reasons: its letters are irregular enough to be individually distinctive.
How to Use Dyslexic Fonts on Your Devices
If you still want to try OpenDyslexic, it’s easy to set up. On Amazon Kindle devices (Paperwhite, Voyage, and basic Kindle models from the third generation onward), OpenDyslexic comes preinstalled. Open any book, tap the top of the page to access display settings, and select OpenDyslexic from the font menu. Older Kindle models (first and second generation) don’t support it natively, but you can download the font from opendyslexic.org.
On computers, you can install OpenDyslexic as a system font and use it in word processors, or add a browser extension that converts web text. Chrome and Firefox both have OpenDyslexic extensions available in their add-on stores. On iOS and Android, the font can be installed through accessibility settings or third-party apps, though the process varies by device.
What Actually Helps Dyslexic Readers
The research points to a few formatting changes that consistently improve readability for people with dyslexia, none of which require a special font:
- Increase letter spacing by a small amount, roughly 1 point extra on 14-point text. This alone has shown measurable reading improvements in multiple studies.
- Increase word spacing as well, adding about 3 to 4 extra points between words at the same text size.
- Use at least 14-point font size with generous line spacing (around 1.5 times the font size).
- Left-justify text rather than full-justify, which keeps word spacing consistent across each line.
- Choose a clean sans-serif font like Arial or Verdana, or a monospaced font like Courier.
These adjustments are available in virtually every word processor, e-reader, and web browser. They’re free, they work with any font, and unlike specialized dyslexia fonts, they have solid evidence behind them. The appeal of a “dyslexia font” is understandable, but the real gains come from how text is spaced, not from the shapes of the letters themselves.