In this walkthrough, we've shared how to underline text in InDesign, so you can create custom underlines, special effects, and more.
How to Underline Text in InDesign
To create a basic underline, first highlight the text that you wish to adjust—either by clicking and dragging over the text, or triple-clicking to quickly select an entire section. Then, click on the Underline icon (it looks like a T with a line underneath it) to add it to your text.
Drawing Custom Lines
InDesign's Underline function is the easiest method for adding underlines, but if you want more control over the line position, thickness, and color, you can also create a line from scratch. To do this, select the Line tool from the Tools panel (it looks like a diagonal line). Then, draw a line under the desired text while holding the Shift key, so that it stays perfectly horizontal.
From here, you can customize any aspect of your line by changing settings in the control panel, or adjust the line color in the Swatches panel. With the line selected, you can adjust its position with the arrow keys, or drag on the ends to extend the line in either direction.
Adding Advanced Underlines
Custom lines offer way more flexibility than a normal underline, but you may run into issues if you decide to move the text. Since your line is a separate object in the project, you'll have to adjust it every time you resize or reposition the text.
To avoid these problems, you can create a normal underline and then tweak it by selecting "Type" > "Character" to open the Character panel. If you left-click on the dropdown arrow in the top right corner of the panel and choose "Underline Options", you'll see a new dialog box. Here, you can adjust settings like Weight (i.e. underline thickness), Offset (the space between underline and text), Color, and more.
To extend the underline past your text, just access the Paragraph panel ("Type" > "Paragraph"), right-click on the panel's dropdown arrow, and choose "Paragraph Rules". In the dialog box, choose "Rule Below" and then adjust the various line settings. In the Width section, if you choose "Column", the line will span the entire column. From there, you can shorten the line length with the Left Indent and Right Indent settings.