What is bionic reading?

Bionic reading is a text-formatting technique that bolds the first part of each word, leaving the rest unbolded. The idea is that your eyes and brain can use the bolded fragment to recognize the word faster, guiding your reading and potentially helping focus and speed.

Is my file uploaded anywhere?

No. Pasted text stays in your browser tab, and uploaded PDF, FB2, or EPUB files are parsed locally with JavaScript — nothing is sent to a server.

What file types can I upload?

PDF, FB2, and EPUB. Text is extracted from each format's own structure (PDF page text, FB2 paragraphs, EPUB spine chapters) and re-assembled into paragraphs for the reading pane.

What do the intensity levels change?

Intensity controls how much of each word gets bolded — roughly 30% of the letters at Light, 40% at Medium, and 50% at Strong. Longer words get proportionally more of their letters bolded; very short words always get at least one bolded letter.

What formats can I download?

PDF, FB2, and EPUB, all generated with the bionic bolding already applied at your chosen intensity, so the file reads the same way on any device or e-reader that supports bold text.

Will formatting like images, tables, or columns survive?

No — this tool extracts plain paragraph text only. Layout, images, tables, and columns from the source PDF/FB2/EPUB are not preserved; the output is reflowable bionic-formatted text.

BIONIC READING

Paste text or upload a PDF, FB2, or EPUB, read it bionic-formatted right here, and download the result. Nothing leaves your browser.

Intensity

Font size18px

Bionic reading bolds the first part of each word so your eyes can guess the rest, which can make skimming feel faster.

Paste your own text above, or upload a PDF, FB2, or EPUB file to convert a whole document instead.

How to use the Bionic Reading tool

1
Paste text, or switch to Upload and choose a PDF, FB2, or EPUB file.
2
Pick a bolding intensity (Light, Medium, or Strong) and a comfortable font size.
3
Read the bionic-formatted text right in the reading pane.
4
Download the result as a PDF, FB2, or EPUB file with the bionic bolding baked in.

Questions

What is bionic reading?: Bionic reading is a text-formatting technique that bolds the first part of each word, leaving the rest unbolded. The idea is that your eyes and brain can use the bolded fragment to recognize the word faster, guiding your reading and potentially helping focus and speed.
Is my file uploaded anywhere?: No. Pasted text stays in your browser tab, and uploaded PDF, FB2, or EPUB files are parsed locally with JavaScript — nothing is sent to a server.
What file types can I upload?: PDF, FB2, and EPUB. Text is extracted from each format's own structure (PDF page text, FB2 paragraphs, EPUB spine chapters) and re-assembled into paragraphs for the reading pane.
What do the intensity levels change?: Intensity controls how much of each word gets bolded — roughly 30% of the letters at Light, 40% at Medium, and 50% at Strong. Longer words get proportionally more of their letters bolded; very short words always get at least one bolded letter.
What formats can I download?: PDF, FB2, and EPUB, all generated with the bionic bolding already applied at your chosen intensity, so the file reads the same way on any device or e-reader that supports bold text.
Will formatting like images, tables, or columns survive?: No — this tool extracts plain paragraph text only. Layout, images, tables, and columns from the source PDF/FB2/EPUB are not preserved; the output is reflowable bionic-formatted text.