How to open ONETOC files

Did your computer fail to open an ONETOC file? We explain what ONETOC files are and recommend software that we know can open or convert your ONETOC files.

What is an ONETOC file?

The ONETOC file extension indicates to your device which app can open the file. However, different programs may use the ONETOC file type for different types of data.

While we do not yet describe the ONETOC file format and its common uses, we do know which programs are known to open these files, as we receive dozens of suggestions from users like yourself every day about specific file types and which programs they use to open them.

We are continually working on adding more file type descriptions to the site, so if you have information about ONETOC files that you think will help others, please use the Update Info link below to submit it to us - we'd love to hear from you!

Various ONETOC openers

These apps are known to open certain types of ONETOC files. Since many different programs may use ONETOC files for different purposes, you may need to try a few of the apps to open your specific ONETOC file.

Microsoft OneNoteMicrosoft OneNoteUser submitted
Microsoft OfficeMicrosoft OfficeUser submitted
Microsoft Office Mondo - EnglishMicrosoft Office Mondo - EnglishUser submitted
V-ToolsV-ToolsUser submitted

Try a universal file viewer

Try a universal file viewer like Free File Viewer. It can open over 200 different types of files - and most likely yours too. Download Free File Viewer here.

We have not verified any programs that we know for certain can work with ONETOC-files on Mac. If you know one, please use the Suggest link below and tell us about it!
We have not verified any online services that we know for certain can work with ONETOC-files. If you know one, please use the Suggest link below and tell us about it!