What is a .one file?

How to open a .one file

• The program that created it is by far the most reliable way to open it.
• On Windows, use a hex viewer or the free TrID tool to identify what the file really is.
• On Mac or Linux, running `file yourfile` in the terminal identifies most formats instantly.

The registry records this extension against Microsoft OneNote, so software from that family is the most likely match.

How to convert a .one file

• Identify the file first, then look for an export or Save As option in whatever program can read it.

MIME type

When a .one file travels over the web, servers label it with this MIME type:

What's a MIME type?

The technical record

For archivists, developers and the merely curious: these are the PRONOM registry entries for .one.

Got another one?