Bionic Reading Converter
Bold the opening of every word to give your eye something to land on.
What It Does, And What The Evidence Says
The idea is simple enough to test: your eye recognises a word largely from its opening letters, so emphasising that part gives the eye a fixation point and the rest is filled in. Bolding the first half of every word is what that looks like in practice.
Whether it makes anyone read faster is genuinely unsettled. The studies that exist are small and disagree with each other, and the strongest claims made for it are not supported. What is not in dispute is that a good many people find it easier to hold their place on a line and to keep going through a long passage — which is a real benefit even if it is not the one originally advertised. Try it on something you actually have to read, and trust your own experience over anybody's claim.
Key features
- Adjustable emphasis — from a fifth of each word to four-fifths.
- Short words skipped — bolding "a" and "of" adds noise rather than signal; the threshold is yours to set.
- Punctuation handled properly — the bold starts at the first letter, not at an opening bracket or quotation mark.
- Copies with the bold — pastes into a document as formatted text, not a wall of plain words.
- Comfortable reading settings — larger text and roomier lines, and a self-contained HTML export.
This tool runs entirely inside your browser using native Web APIs. Your files and text are never uploaded to a server, never logged and never shared with third parties.
How to use: Bionic Reading Converter
- Paste your text
An article, a chapter, a set of notes — anything long enough to read properly. - Set how much to emphasise
Half is the usual starting point; less is subtler and often easier on the eye. - Adjust the reading size
Roomier lines help as much as the bolding does, for many people. - Copy or save
Copying keeps the formatting. The HTML export is a standalone page you can keep.
Technical specifications
| Processing location | Entirely in your browser — no server round trip |
|---|---|
| Data uploaded | None. Files and text never leave your device |
| Price | Free — no account, no trial, no usage cap |
| Category | Text |
| Works offline | Yes, once the page has loaded |
| Browser support | Chrome 90+, Edge 90+, Firefox 90+, Safari 15+ |
| Interface languages | English, 中文, हिन्दी, Español, العربية |
Frequently asked questions
Does bionic reading actually work?
The evidence is mixed and thin. Several small studies have found no significant speed improvement, and the largest claims made for it have not been replicated. Some readers report that it helps them stay on the line and sustain attention, which is a different benefit from speed and a real one. It costs nothing to try on a page you have to read anyway.
Does it help with ADHD or dyslexia?
Some people with either report that it helps, and there is no good trial evidence either way. It is not a treatment and no one should present it as one. As a free thing to try alongside whatever actually works for you, it is harmless.
Why is the bold not exactly half the word?
Because a word cannot be split at half a letter. The cut is rounded to the nearest character with at least one letter always emphasised, so a three-letter word gets one or two rather than one and a half.
Will the bold survive pasting into Word?
Yes. The copy button puts both rich text and plain text on the clipboard, so a word processor takes the formatted version and a plain text editor takes the plain one. Each gets what it can use.
Can I apply this to a whole website?
Not from here — this converts text you paste. Browser extensions exist that do it to any page, with the usual caveat that an extension can read everything you browse. For a single article, pasting it here reveals nothing to anyone.