How to Add a Horizontal Divider in OneNot

A horizontal line can make longer notes much easier to scan. However, OneNote does not provide a standard horizontal divider that automatically stretches across the full width of the text area. Fortunately, there is a simple text-based workaround that works well for everyday notes.

The simple underscore method

Type a row of underscores _ to create the appearance of a continuous horizontal line:

Text above the line 
___________________________________________________________________

Text below the line

Underscores work particularly well because the individual characters appear connected, creating a cleaner line than multiple hyphens (---).

Around 50 to 100 underscores are usually enough. The line does not need to reach the exact right edge of the page—the goal is simply to create a clear visual separation between sections.

Adding an empty line after the divider also creates comfortable spacing between the line and the following content.

What are the alternatives?

You can use OneNote's Draw tools to insert a straight line, but its length is fixed and does not automatically adapt to the width of your content. A table can also be used as a visual separator, although this is unnecessarily cumbersome for such a simple task.

For everyday notes, the underscore method is therefore a quick, clean, and reusable solution.