Today i noticed long replication times for one of my OneNote Notebooks when i opened it on my iPhone. I remembered that i insert a PDF file into it. So i checked the file size of the Notebook via OneDrive. I saw that this file was 10 MB big.
I tried to reduce the file size by deleting the PDF file from the Notebook. But this doesn’t help.
Second try was to delete the Notebooks recycle bin. This also doesn’t help. Therefore i had to dig a bit deeper.
Searching Google offers me a lot of descriptions of how to shrink OneNote file via “Tools–> Options, Save tab – Optimize All Files Now button”. Sadly this is not possible with OneNote for Mac.
My next try was to download the OneNote file from OneDrive. While doing this, i got a ZIP file with all my OneNote Notebooks in it. Examining this ZIP file gives me the information that every Section in a OneNote Notebook is a single .one file. So this gives me the information that the problem is not the Notebook itself. The problem is at the Section level. Once the space is allocated it will never released.
With this information the solution was pretty easy. I identified the Section with the waste of space and copied the information to a new Section. Then i deleted the old one and emptied the recycle bin of the Notebook. After that the size of the Notebook dropped down significant.