What Is a ONEPKG File?

How to open, edit, & convert ONEPKG files

A file with the ONEPKG file extension is a Microsoft OneNote Package file. A file like this serves as a type of archive file for the MS OneNote program.

ONEPKG files contain multiple OneNote Document (.ONE) files and can be produced in Microsoft OneNote by backing up a notebook full of pages.

Another file contained in a ONEPKG file is a Microsoft OneNote Table of Contents File (.ONETOC2) that stores the organizational information on how the different sections of the document have been arranged.

How to Open a ONEPKG File

Screenshot of several ONEPKG files in Windows 10 that MS OneNote uses

ONEPKG files are opened by Microsoft's OneNote tool. You can download OneNote free from Onenote.com.

You can back up your own .ONE files to a .ONEPKG file through OneNote's File > Export > Notebook menu option. Just choose to export the notebook to a OneNote Package file.

When you open the ONEPKG file, OneNote will ask where you want to extract its contents. The folder you choose will then be used to hold all the .ONE files that were contained within the ONEPKG file.

Unpack Notebook prompt in OneNote

If you don't have OneNote installed but you still want to extract the .ONE files, you can use a free file unzip utility like 7-Zip. Opening it this way is basically the same as with using OneNote, but you'll still need the OneNote program installed in order to open the .ONE files.

ONEPKG archive in 7-Zip

Another option for opening the ONEPKG file as an archive is to just rename the .ONEPKG extension to .ZIP. In Windows, you can easily open the new ZIP file without any extra software. Once open, you'll see all the .ONE files.

ONEKPG files are an exception when it comes to renaming the file extension and still having the file work like it does. Most file types cannot just be renamed to something else and still function normally in the program that opens it. DOCX files, for example, can't be renamed to PDF and expected to be opened and readable in a PDF reader.

If you find that an application on your PC does try to open the ONEPKG file but it's the wrong application or you'd rather have another installed program open ONEPKG files, see our How to Change the Default Program for a Specific File Extension guide for making that change in Windows.

How to Convert a ONEPKG File

ONEPKG files themselves can't be converted to any other format. They're basically just containers for holding other OneNote files, so there's simply no reason to convert this archive to another archive format.

However, you can convert specific OneNote documents (not the .ONEPKG file) to PDF, XPS, and MHT files through the File > Export menu in OneNote.

OneNote export options

If you're looking to "convert" a ONEPKG file to a ONE file, use the information above to extract the ONE files out of the archive. There aren't any file conversion tools necessary for this to take place.

Still Can't Open the File?

If your file won't open with OneNote, there's a really good chance that you're misreading the file extension. If this happens, your file won't open normally in OneNote because it's probably in an entirely different file format.

For example, PACKAGE files might at first glance appear to be related to ONEPKG files but they're really Electronic Arts Games Package files used by Electronic Arts games. You can't use one with a Microsoft program, they won't work with OneNote, and they're unrelated to any popular note taking app.

PKG is similar but it's the file extension reserved for other unrelated formats like Symbian Package, Mac OS X Installer Package, PlayStation Store Downloaded Package, and others.

If your file doesn't actually end in ONEPKG, research the real file extension to learn more about the program you need on your computer to open it, to convert it to a different format, or to edit it.