Bionic Reading Converter
Bold the first few letters of every word to skim faster — paste text or open a PDF or EPUB, and save it back as a PDF or image. 100% in your browser.
How much of each word to bold — lower is a lighter touch, higher is bolder.
🔒 Everything runs in your browser — your text is never uploaded. Bionic-style reading bolds the start of each word to guide your eyes, which can aid focus and skimming speed.
What is bionic reading?
Bionic reading is a formatting technique that makes only the first part of each word bold. Those bold openings act as visual anchors: your eyes jump from one anchor to the next while your brain fills in the lighter tail of each word, so a paragraph can be scanned faster and with less effort. This tool applies that effect to any text you paste and shows the result live as you type. A fixation slider controls how much of each word is emphasized, from a light touch that bolds one or two letters to a heavier setting that covers most of the word.
How to use it
Paste or type your text in the box, then drag the fixation slider between 30 and 70 percent to taste. The preview updates instantly so you can see exactly how the page will read. When you are happy with it, switch the output to HTML to copy ready-to-paste markup for a blog, newsletter, or web page, or switch to Markdown to drop the emphasis into notes and documents. You can also open a whole PDF or EPUB instead of pasting, read it in a full-screen view, fade the tail of each word with the Contrast control, and download the result as a PDF or a PNG image. Everything runs locally in your browser, so even long or private documents never leave your device.
Frequently asked questions
What does the fixation slider do?
Fixation controls how many letters at the start of each word are bolded. It is calculated as the ceiling of the word length times the fixation value, so at 50 percent a five-letter word gets its first three letters bolded. A lower setting is a lighter, subtler guide; a higher setting bolds more of each word for a stronger pull. Single-letter words are always fully bolded.
Does bionic reading actually make you read faster?
Results vary from person to person. Many readers find the bold anchors help them keep their place and skim more comfortably, which can aid focus, and some people with attention differences prefer it. Independent studies have been mixed on raw speed, so treat it as a helpful reading aid to try rather than a guaranteed boost. Because it is free and instant here, the easiest test is to paste your own text and see whether it helps you.