What Is a Dyslexia-Friendly Font?
By Yechiel Kuperman, marine biologist · 49 years keeping fish
Quick answer
A dyslexia-friendly font is a plain typeface in which no letter is easily mistaken for another — b, d, p and q each get their own shape — printed with generous space between letters, words and lines.
The research is blunt about which half matters: the special letter shapes have never produced a measured reading gain, while the spacing those fonts ship with has.
So when you pick up a book, judge the room on the page before the shapes of the letters.
The numbers
| Feature | What the research shows | How strong the evidence is |
|---|---|---|
| Wider letter AND word spacing together | Faster, more accurate reading | Strong — the effect usually credited to the special fonts themselves |
| Special dyslexia letterforms alone | No measurable improvement | Strong evidence of no benefit; most children tested preferred plain Arial |
| Wider letter spacing on its own | Reading gets slower, not faster | Strong. The ratio matters — word gaps must grow with letter gaps |
| Plain sans-serif over serif or italic | Faster reading, shorter eye fixations | Moderate — one eye-tracking study of readers aged 11 to 50 |
| Distinct b/d/p/q and I/l/1 letterforms | No controlled reading trial | Sensible design consensus, untested as a standalone change |
| Atkinson Hyperlegible specifically | No published reading study exists | Untested. A careful free choice — the one our own books use |
Do this — step by step
- Open the book to ordinary text and find a lowercase b, d, p and q to compare.In a friendlier typeface each has its own shape, not one shape rotated four ways
- Check that a capital I, a lowercase l and the digit 1 look different from each other.The classic trap trio in children's print
- Look at the gaps: the space between words should read as clearly wider than the space between letters.
- Check for clear air between one line and the next.Around one-and-a-half line spacing is the comfortable band
- Prefer plain, upright sans-serif over anything decorative, condensed or italic.
- Check the lowercase letters stand tall relative to the capitals.A large x-height keeps small print legible
- Ignore a “dyslexia font” claim on the cover as a buying signal — the inside page is the evidence.
- On an e-reader, widen the spacing settings before you swap the typeface.Most readers let you open up line spacing for free
What actually makes a letter easy to recognise?
Start with what reading asks of the eye. Before a word can be recognised, each letter in it has to be identified, and letters are identified by shape. Most of the alphabet is fine. A handful of letters are not.
Lowercase b, d, p and q are the famous offenders. In many typefaces they are literally one shape in four rotations, and young readers — dyslexic or not — routinely flip them while letter recognition is still settling in.
A thoughtfully designed reading typeface gives each of those letters its own silhouette, so the shape alone says which letter it is. It also keeps capital I, lowercase l and the digit 1 from collapsing into one vertical stroke.
That is the letterform half of the story, and it is the half everyone talks about. The measured half is spacing.
When a special dyslexia typeface was tested against ordinary Arial, struggling readers did read it a little faster — until the researchers widened Arial's letter and word spacing to match. Then the difference vanished. The gain had been living in the gaps all along.
Two further studies looked for a benefit from the special letterforms directly, in children with and without dyslexia. Neither found one, and most of the children preferred the ordinary font.
Spacing has its own trap, though: it is a ratio, not an amount. Widening the letter gaps without widening the word gaps makes every word wider while its boundaries get vaguer, and reading gets slower rather than faster.
Eye-tracking adds one duller finding: plain sans-serif type outperforms serif and italic. Nothing exotic — clean, even, unslanted letters are simply easier for the eye to land on.
None of this is only about dyslexia. Crowded, ambiguous print taxes whoever is reading it, and it taxes hardest the reader with the least capacity to spare — which very much includes the reluctant reader who merely finds reading expensive.
So the honest summary of a dyslexia-friendly font is this: unambiguous letters are sensible, spacing is what the evidence actually supports, and together they make a page that asks less of a tired reader.
By the way, out in the ocean…
Dolphin. Famous for intelligence and play — dolphins solve problems and call each other by name with signature whistles. Dolphins tell each other apart by signature whistles — readers tell letters apart by clear, distinct shapes.
Manta ray. It glides on wing-like fins up to seven metres across — a giant so gentle it eats only tiny drifting plankton. Its glide is easy to watch the way a clear typeface is easy to read: nothing snags and nothing blurs.
From 49 Years at the Farm
Yechiel, on the typeface his own books are printed in
I am dyslexic. The books carry my name because I tell the stories — somebody else does the typing.
So when it came time to print them, I was not choosing a typeface the way a designer would. I was choosing it the way a reader would.
They are set in Atkinson Hyperlegible, at one and a half line spacing. I picked the spacing first and the typeface second, and that order was deliberate.
Nobody has published a study proving Atkinson Hyperlegible makes reading faster, and I will not pretend otherwise. It is a careful choice, its letters cannot be mistaken for each other, and it is free.
The spacing is the part I would argue for. Words with room around them stop looking like work.
Pinchy’s Logbook Card
Hermit crab · connoisseur of well-fitting shapes
Pinchy has strong views on shells, which is to say on shapes. A shell that almost fits is worse than no shell at all, and in his opinion a letter that almost looks like another letter is the same disgrace.
He inspected the b and the d in these books and reports, grudgingly, that they are different shapes and not one shape doing a handstand. He approves. He would like it noted that approving of something takes a great deal out of him, and that he will not be doing it again soon.
What goes wrong when parents shop for a font
Paying for a special dyslexia typeface
The tested dyslexia fonts showed no reading gain from their letter shapes, and in the studies most children preferred the ordinary font. What those products reliably deliver is generous default spacing — which nobody needs to buy.
If a book you like happens to use one, that is no reason to reject it. It is just not a reason to choose it either.
Treating the font as the treatment
Typography lightens the load; it does not teach decoding. A child who struggles to read needs reading instruction, and no page layout substitutes for it.
Think of a well-set page the way you think of good lighting: it removes an obstacle. The learning still has to happen.
Choosing the font that looks friendliest
Rounded, bouncy, handwriting-style print looks warm on a cover and is often harder to read in bulk — decoration on the letters is exactly what a working eye does not need.
Plain and open beats cute. The friendliest typeface on the shelf is usually the most boring one.
Making the print bigger instead of giving it room
Size and spacing are different levers. Enlarged print with the same cramped gaps is the same wall of text, only larger.
If you can change one thing, open up the space between words and lines. That is the lever the research supports.
Judging the typeface from the cover
Covers are set in display type that has nothing to do with the inside of the book. Open it to a full page of ordinary text near the middle and judge that.
One minute with an inside page tells you more than everything printed on the outside.
Questions we get asked
What is the best font for dyslexia?
There is no single proven best. The research supports plain, unambiguous sans-serif letters with generous space between letters, words and lines — a description many ordinary typefaces meet when they are set well.
In the controlled studies, most children actually preferred plain Arial to the fonts designed for them.
Do fonts like OpenDyslexic or Dyslexie actually work?
Not through their letter shapes, as far as anyone has measured. Two studies found no reading advantage from the letterforms, and the one apparent speed gain disappeared when an ordinary font was given the same spacing.
Their honest contribution is that they ship with wide spacing switched on by default.
What font are your books printed in?
Atkinson Hyperlegible, at one-and-a-half line spacing — chosen by a dyslexic author for its unmistakable letterforms and set with the spacing the research supports.
No published study has measured that specific typeface yet, and we say so plainly rather than borrow evidence it does not have.
Is Comic Sans good for dyslexia?
It gets recommended surprisingly often, and its letterforms are genuinely distinct, which is the sensible half of the advice. There is no controlled evidence it improves reading.
If a child likes it, it does no harm. The spacing around the letters still matters more than the letters.
Does any of this matter for a child who is not dyslexic?
Yes. Crowded print penalises whoever reads it, and the penalty lands hardest on new and reluctant readers, whatever the reason reading feels hard.
A generously spaced page is simply cheaper to read — which is why our books for ages 7–10 are set that way for every child, not only dyslexic ones.
What should I check when buying a children's book?
Open a middle page and look for word gaps clearly wider than letter gaps, clear air between lines, a b and d with different shapes, plain upright type, and a text block free of decoration.
That sixty-second check beats any label on the cover, and our book-buying guide walks through it page by page.
Can I make an e-reader dyslexia-friendly?
Mostly, and the settings that matter are free: widen the line spacing first, then the margins to shorten the lines, then try the built-in typefaces.
Change the spacing before you change the font. That is the order the evidence supports.
Sources
- marinus2016Marinus, E., Mostard, M., Segers, E., Schubert, T. M., Madelaine, A. & Wheldall, K. (2016). A Special Font for People with Dyslexia: Does it Work and, if so, why? Dyslexia 22(3), 233–244. View sourceNote: The study most often cited FOR dyslexia fonts, and read in full it argues the opposite: the advantage disappeared once ordinary Arial was matched for spacing.
- kuster2018Kuster, S. M., van Weerdenburg, M., Gompel, M. & Bosman, A. M. T. (2018). Dyslexie font does not benefit reading in children with or without dyslexia. Annals of Dyslexia 68, 25–42. View source
- wery2017Wery, J. J. & Diliberto, J. A. (2017). The effect of a specialized dyslexia font, OpenDyslexic, on reading rate and accuracy. Annals of Dyslexia 67(2), 114–127. View source
- galliussi2020Galliussi, J., Perondi, L., Chia, G., Gerbino, W. & Bernardis, P. (2020). Inter-letter spacing, inter-word spacing, and font: something to worry about when designing texts for people with dyslexia? Annals of Dyslexia 70(1), 141–152. View sourceNote: Found extra letter spacing impairs reading speed unless word spacing grows with it.
- rello2013Rello, L. & Baeza-Yates, R. (2013). Good fonts for dyslexia. Proceedings of the 15th International ACM SIGACCESS Conference on Computers and Accessibility (ASSETS '13). View source
- brailleinstituteBraille Institute of America. Atkinson Hyperlegible Font. Designed with Applied Design Works, released 2019. View sourceNote: The typeface's design rationale is well argued, but as of mid-2026 we could find no published, peer-reviewed study measuring a reading gain from it.
- bda-styleguideBritish Dyslexia Association. Dyslexia Friendly Style Guide. View sourceNote: Practitioner guidance rather than a controlled trial — the source of the plain-sans-serif and generous-spacing conventions.
About the author
Yechiel Kuperman
Marine Biologist
Marine biologist. Forty-nine years in fishery and aquarium work.
Chief Scientist of the Israeli Ornamental Aquarium Society for fifteen years, and the developer of specialist fish strains supplied to European importers.
He writes the Yechiel's Fishery Farm books, in which the biology is real and the fish have opinions.
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