---
title: "Fasttabs"
description: "A new font, combining Bionic Reading® with the OpenDyslexic typeface."
pubDate: 2025-01-30T00:00:00.000Z
updated: 2025-07-19T00:00:00.000Z
tags: ["typography"]
---

import Sidenote from "@/components/sidenote.astro";
import Tabs from "@/components/tabs.astro";

<style>{`
@font-face {
	font-family: 'OpenDyslexic';
	src: url('/fonts/OpenDyslexic-Regular.woff2') format('woff2'),
	     url('/fonts/OpenDyslexic-Regular.woff') format('woff'),
	     url('/fonts/OpenDyslexic-Regular.otf') format('opentype');
	font-weight: normal;
	font-style: normal;
	font-display: swap;
}

@font-face {
	font-family: 'FastOpenDyslexic';
	src: url('/fonts/OpenDyslexic-Fast.otf') format('opentype'),
	     url('/fonts/OpenDyslexic-Fast.ttf') format('truetype');
	font-weight: normal;
	font-style: normal;
	font-display: swap;
}
`}</style>

# Fasttabs

In 2022, the company *Bionic Reading AG* released [Bionic Reading®](https://bionic-reading.com), a new method to increase reading speed by highlighting the most concise parts of words, which rapidly guides the eyes through the text. In practise, it looks like the following:

<div class="border border-gray-300 *:my-0 pt-4 px-4 mt-4 mb-8">
<Tabs labels={["Use Bionic Reading ✨", "Switch to plain text"]}>
<div slot="tab-1">
**Ca**ll **m**e **Ishm**ael. **So**me **yea**rs **a**go- **nev**er **mi**nd **h**ow **lo**ng **preci**sely- **hav**ing **lit**tle **o**r **n**o **mon**ey **i**n **m**y **pur**se, **a**nd **noth**ing **parti**cular **t**o **inte**rest **m**e **o**n **sho**re, **I** **thou**ght **I** **wou**ld **sa**il **abo**ut **a** **lit**tle **a**nd **s**ee **t**he **wat**ery **pa**rt **o**f **t**he **wor**ld. **I**t **i**s **a** **w**ay **I** **ha**ve **o**f **driv**ing **o**ff **t**he **spl**een **a**nd **regul**ating **t**he **circul**ation. [...]
</div>
<div slot="tab-2">
Call me Ishmael. Some years ago- never mind how long precisely- having little or no money in my purse, and nothing particular to interest me on shore, I thought I would sail about a little and see the watery part of the world. It is a way I have of driving off the spleen and regulating the circulation. [...]
</div>
</Tabs>
</div>

Does it work? Maybe.<Sidenote>*Update July 2025*: An experiment on 2074 testers [found no evidence that Bionic Reading has a positive effect on reading speed](https://blog.readwise.io/bionic-reading-results/). Readers were roughly as fast with Bionic Reading as they were without.</Sidenote> It feels a bit faster than plain text for me?

[OpenDyslexic](https://opendyslexic.org/) on the other hand aims to help with symptoms of dyslexia - letters have heavy weighted bottoms and unique letter shapes, and the extra-large letter spacing renders the reading material more easily accessible.<Sidenote>Zorzi, M., et al. (2012). Extra-large letter spacing improves reading in dyslexia. *Proceedings of the National Academy of Sciences*, *109*(28), 11455–11459. https://doi.org/10.1073/pnas.1205566109</Sidenote>

<div class="border border-gray-300 *:my-0 p-4 mt-4 mb-8" style="font-family: 'OpenDyslexic', sans-serif;">
Call me Ishmael. Some years ago- never mind how long precisely- having little or no money in my purse, and nothing particular to interest me on shore, I thought I would sail about a little and see the watery part of the world. It is a way I have of driving off the spleen and regulating the circulation. [...]
</div>

If you combine the two, you get an unholy abomination which drags your eyes down the page faster than your neurons can process the pixels - at least in theory. Nevertheless, a friend of mine specifically requested it.

## The process

Their website gives you multiple options for using Bionic Reading on your device. For our purposes, we will be modifying the webfont, which you can download and install on all your devices locally, provided you pay them a small fee of $79.00 dollars first.

But wait a second - All you get is a font! How does a font alone control which letters of a word are highlighted?

The answer lies in a so called "Feature", instructions baked into the font file that tell your text renderer "when you see *this* character pattern, replace it with *this* instead". They make a font smarter than just a static mapping from character -> shape.

Most of the time, this is used for ligatures - two symbols joining together to form a single glyph. This improves readability in serif fonts where some characters often collide with one another, as shown in the following example:

<div class="border border-gray-300 *:my-0 pt-4 px-4 mt-4 mb-8">
<Tabs labels={["With ligatures", "Without ligatures"]}>
<div slot="tab-1" class="text-4xl sm:text-6xl">
fi fj fl ffi gg gy
</div>
<div slot="tab-2" class="text-4xl sm:text-6xl [font-variant-ligatures:none]">
fi fj fl ffi gg gy
</div>
</Tabs>
</div>

Most of the time, the mechanism is simple - Switch out one character for another if the character is preceded by a certain letter. But it can also be used for more... interesting purposes, as seen in Bionic Reading.

The font contains two versions of every letter: a normal one (`a`) and a bold one (`a.bold`). An OpenType feature defines the rules for when to swap. Depending on the word length, the font feature tracks how many letters are present in a word and then bolds a calculated number of letters at the start. For example, a 1-3 letter word gets just the first letter bolded, a 4-6 letter word gets the first two bolded, a 7-8 letter word gets the first three, and so on - scaling up for longer words.

<div class="border border-gray-300 *:my-0 pt-4 px-4 mt-4 mb-8">
<Tabs labels={["Use Bionic Reading ✨", "Switch to plain text"]}>
<div slot="tab-1">
**I** **a**m **o**ne **st**ep **be**hind
</div>
<div slot="tab-2">
I am one step behind
</div>
</Tabs>
</div>

This makes the Bionic Reading font work on most devices that support OpenType features - and it also means we can extract it and use it for another font...

## The result

I call it Fasttabs, after the friend who helped inspire it. Here you go, Tabs. I absolutely hate it, but I hope you have fun.

<div class="border border-gray-300 *:my-0 p-4 mt-4 mb-8" style="font-family: 'FastOpenDyslexic', sans-serif;">
Call me Ishmael. Some years ago- never mind how long precisely- having little or no money in my purse, and nothing particular to interest me on shore, I thought I would sail about a little and see the watery part of the world. It is a way I have of driving off the spleen and regulating the circulation. [...]
</div>

[You can download Fasttabs here.](/files/FastOpenDyslexic.zip)