Bionic Reading–Style Text Converter

Bold-start text, popularised as “bionic reading”, bolds the first part of each word. The idea is that the eye catches the bold letters and the brain fills in the rest, letting you move through text with less effort. Some readers, including some with ADHD, say it helps them stay focused on long passages. This converter applies the formatting to any text so you can try it on your own reading.

What research has found

Controlled studies so far have not found an average gain in reading speed or comprehension compared with ordinary text, and some found it slightly slower for most readers. That does not mean nobody benefits; preferences differ, and comfort matters if it keeps you reading. Treat it as an experiment rather than a fix.

The settings

The bold share sets how much of each word is bold, from a fifth to seven tenths, rounded to whole letters with at least one letter per word. At the default 45%, “Reading quickly is fun” bolds Rea, qui, i and f. You can bold every word, or only every second or third, which some readers find calmer. Skipping short words leaves little words like “is” and “of” alone. The weight runs from semibold to heavy, and the preview size lets you judge it at your normal reading size.

Using the formatted text

“Copy formatted” places two versions on the clipboard: HTML with bold, and the original text without it. Word, Google Docs, Pages, Outlook, Gmail and most note apps take the bold version. The Markdown copy uses double asterisks for apps such as Obsidian. Downloading an HTML page gives a comfortable reading layout with your chosen weight and size, which you can open on any device.

Accessibility considerations

Screen readers read the bold version normally, because the words are not broken into separate pieces in the HTML. The plain-text copy is your original text, so search, spell-check and translation still work on it. Avoid using bold-start formatting in materials for other people without offering a normal version; for many readers it adds visual noise.

A fair test on yourself

Pick two passages of similar difficulty and length from the same source. Read one normally and one formatted, timing yourself and writing three key points from each without looking back. Swap which passage gets the formatting on another day. If the formatted version is consistently faster or easier to remember, it suits you; if not, normal text is just as good.

Other ways to read more comfortably

Shorter line lengths, larger text, more line spacing and a font you find clear help most readers. Reading aloud with text-to-speech, or one word at a time with a speed reader, are alternatives worth comparing.

Choosing settings that feel right

If the text feels heavy, lower the bold share to 30–35% and use semibold. If you still lose your place, try emphasising every second word only. Larger text sizes need less bold; small text on a phone may need a little more.

Related tools

Read one word at a time with the RSVP Speed Reader, have text read aloud with Text to Speech, check how hard a passage is with the Readability Checker, or scroll a script at a set pace with the Online Teleprompter.