.one.onetoc2
OneNote .one files: what they are and how to open them
A .one file is one OneNote section, a stack of pages. Open it offline on Android or Windows in Universal File Opener, without OneNote or a Microsoft account, as pages with text, lists, tables and pictures.
Check your OneNote file here
Nothing is uploaded. This page names the type and shows its details; to view it, use an app below.
What is a OneNote file?
A OneNote notebook is a folder of sections. Each section is one .one file, and a .onetoc2 file lists the sections. OneNote pages are free canvases where text, pictures, ink and file attachments can sit anywhere.
OneNote on Windows opens a loose .one file. OneNote for Mac and for the web work with notebooks in OneDrive or SharePoint instead. Universal File Opener reads a section from a backup or an email attachment directly, on Android or Windows.
What is inside
A .one file is not XML. It is a binary store of revisions that Microsoft documents as MS-ONESTORE. OneNote 2010 and later files keep a log of changes, and the current page content is whatever the latest revisions say.
The reader follows the saved revisions and page order. It lays out text with its formatting, lists, tables, embedded PNG and JPEG pictures and attachment names in reading order. It does not keep the canvas position. Ink, audio and video get a note but do not play.
Work notebook/├─ Open Notebook.onetoc2the list of sections├─ Meetings.onea section of pages└─ Ideas.oneanother sectionHow to open a OneNote file
Windows
- OneNoteFree from Microsoft. Double-click a .one file to open it under Open Sections.
- Universal File Opener for WindowsOursReads the section offline as pages, with search and copy. No Microsoft account. Read only.
Mac
- OneNote for MacFree from Microsoft. Built for notebooks in OneDrive or SharePoint rather than loose .one files.
Android
- Universal File OpenerOursReads the section offline as pages, with search and copy, and no Microsoft account. Free to open and read only.
In a browser
- OneNote for the webOpens notebooks stored in OneDrive. Put the notebook there from the desktop app first.
Won’t open?
OneNote for Mac or the web will not open the file
They open notebooks in OneDrive or SharePoint. On Windows, double-click the .one file to open it in OneNote, or read it in Universal File Opener.
The app refuses the file
Older (OneNote 2007), password-protected, malformed and unsupported files are refused. Ask the owner to export the pages as PDF.
Handwriting, audio or video is missing
Ink, audio and video are noted but not shown or played, and handwriting is not turned into text.
Pages look different from OneNote
The reader orders content for reading and does not keep the canvas positions. Pictures beyond PNG and JPEG, and limits such as 2,000 pages, can leave things out.
Only one section opens
Each .one file is one section. Open the others from the same folder, or open the table-of-contents file to list its sibling sections.
Convert a OneNote file
- To Text, PDF or HTMLOpen the section in Universal File Opener and use Convert. A text copy is free; PDF and HTML copies need Pro. HTML keeps the reading structure, not the OneNote canvas. PDF refuses scripts the bundled fonts do not cover, such as Arabic and Thai.
- To a OneNote notebook in your accountOpen the section in OneNote on Windows, right-click its tab, choose Move or Copy, and pick a notebook stored on OneDrive.
OneNote files in our apps
Universal File Opener reads OneNote 2010 and later sections offline on Android and Windows as pages, with formatted text, lists, tables, pictures and attachment names. Search and copy. Sections are read only.
All Android tools and limits for OneNote files
- Reads the current revision of each page in section order, with lists, tables, embedded PNG and JPEG pictures and attachment names. A table-of-contents file lists its sibling sections.
Limits
- Ink, audio and video are noted but not shown or played. Canvas positions are not kept.
- Older, password-protected and malformed files are refused.
- Limits include 50 MiB, 2,000 pages and 128 pictures.