Data Interchange Format (.dif) is a text file format used to import/export single spreadsheets between spreadsheet programs.

Applications that still support the DIF format are Collabora Online, *Excel, Gnumeric, and LibreOffice Calc. Historical applications that used to support it until they became end of life or no longer acknowledge support of the format are dBase, FileMaker, Framework, Lotus 1-2-3, Multiplan, OpenOffice.org Calc and StarCalc.

*Some implementations caused interoperability problems, notably those of older Microsoft Excel products, see the section below called "Discrepancies in implementations".

A limitation with DIF format is that it cannot handle multiple spreadsheets in a single workbook. Due to the similarity in abbreviation and in age (both date to the early 1980s), the DIF spreadsheet format it is often confused with Navy DIF; Navy DIF, however, is an unrelated "document interchange format" for word processors.