OneNote File Viewer

OneNote keeps notes in its own file types. A section is a .one file, a notebook folder holds several .one files and a .onetoc2 table of contents, and OneNote for Windows can pack a whole notebook into one .onepkg file. These files are easy to receive and hard to open. A teacher shares last year's class notes as a .onepkg, a colleague leaves, and their project notebook turns up on a shared drive as a folder of .one files, or you download a notebook from OneDrive and get a ZIP. Without OneNote on a Windows PC, and signed in to the right account, there is often no way to look inside. This page reads them in any modern browser on a Mac, Chromebook, Linux PC, Android phone or iPhone.

The file is read by onenote.rs, an open-source OneNote parser written in Rust that follows Microsoft's published file format, compiled to WebAssembly and run in a worker inside your tab. It reads sections saved by the OneNote desktop app, sections exported from OneNote for Windows 10 or 11, and notebooks downloaded from OneDrive, which use a different packaging of the same format. Each page shows its title, date and section, then its text with bold, italic, underline, strikethrough, highlight and font size, headings, bulleted and numbered lists with their nesting, tables, links, pictures, attached files, to-do tags and pen drawings.

Search all pages looks through every page title and line of text in the notebook at once and lists the pages that match with a short snippet, which helps when a notebook has hundreds of pages. Download PDF writes all pages into one A4 PDF with real, selectable text, so you can print a notebook, send it to someone without OneNote, or keep an archive copy. All text (.txt) saves every page as plain text with page titles, ready to paste into a document or a notes app. Pictures and files as ZIP saves every picture and every attached file, such as a PDF, Word file or spreadsheet that was dropped onto a page, under its original name.

Notebooks are personal. They hold meeting notes, class notes, passwords someone wrote down, phone numbers and plans. This page does not upload your file. The bytes are read in a separate worker inside this tab, the pages are drawn on your screen, and the PDF, text and ZIP are made on your device. TaskNinja never receives the file or its name, and it is not sent to an AI model. Close the tab and it is gone from memory.

There are limits. Pages are shown in one column, so note containers placed side by side in OneNote appear one under the other. Text colours are shown in black, and fonts are replaced with Liberation Sans in the PDF. Pictures in formats a browser cannot show are listed as a note, though they are still saved in the ZIP. Audio and video recordings cannot be played, equations are shown as plain text, and password protected sections cannot be read. Sections from OneNote 2007 use an older format that this page does not read. A .onetoc2 file holds only the list of sections, not the notes, so choose the .one files next to it instead.