how to use the Istext Formula in Excel to determine whether the cell value is a text or a non text value. Also covered in this video are 1. The N formula 2. The Randbetween formula 3.The IF formula 4. and conditional Vlookup Use the ISTEXT function to check if value is text. ISTEXT will return TRUE when value is text. Steps to how to use Istext formula =ISTEXTA1 will return TRUE if A1 contains "apple". Often, value is supplied as a cell address. ISTEXT is part of a group of functions called the IS functions that return the logical values TRUE or FALSE.