An INDL file is an object library created by InDesign, an application used to create professional page layouts. It may contain graphics, text, and pages, as well as ruler guides, grids, drawn shapes, and grouped images. INDL files allow users to organize and reuse common page elements together.

INDL files can be created by highlighting one or more objects and then selecting File → New → Library. Opened libraries appear on the Object Library panel in the InDesign user interface. Users may add or remove individual objects to an open object library using the Library panel. NOTE: When opening an INDL file from an older software version, InDesign automatically converts the object library to the most recent format.