No matter how many notes you have, you can find them quickly by searching.
Note: If you're new to searching in OneNote, see Tips for searching your notes.
On your keyboard, press Ctrl+F (PC) or Control+F (Mac), or click the magnifying glass icon near the top of the page list.
In the Search box that appears, enter a search word or phrase, and then press Enter.
Just below the Search box, click the arrow to adjust the scope of your search, if necessary. You can search the current Section, or the current Page.
Note: If your notes are stored in OneDrive, you will also see an option to search the current Notebook.
If your search text was found in any of your notes, click to select any page in the list of search results that appears. OneNote Online will open the page you select and then highlight all occurrences of your search text on that page.