You can search for text across a OneNote page, section, or the current notebook.
Tip: Unfortunately, OneNote Online does not currently have a search-and-replace feature. You can only search for text using one keyword at a time.
On your keyboard, press Ctrl+F (PC) or Control+F (Mac), or click the magnifying glass located in the upper left next to 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 Notebook, the current Section, or the current Page.
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.