The word “blank” is somewhat misleading in Excel, because a cell that contains only space will look blank but not be empty. In general, it is best to think of ISBLANK to mean “is empty” since it will return FALSE when a cell looks blank but is not empty. 


If cell A1 contains nothing at all, the ISBLANK function will return TRUE: If cell A1 contains any value, or any formula, the ISBLANK function will return FALSE:

Is not blank

To test if a cell is not blank, nest ISBLANK inside the NOT function like this: The above formula will return TRUE when a cell is not empty, and FALSE when a cell is empty.

Empty string syntax

Many formulas will use an abbreviated syntax to test for empty cells, instead of the ISBLANK function. This syntax uses an empty string ("") with Excel’s math operators “=” or “<>". For example, to test if A1 is empty, you can use: To test if A1 is not empty: This syntax can be used interchangeably with ISBLANK. For example, inside the IF function: is equivalent to: Likewise, the formula: is the same, as: Both will return result1 when A1 is not empty, and result2 when A1 is empty.

Empty strings

If a cell contains any formula, the ISBLANK function and the alternatives above will return FALSE, even if the formula returns an empty string (”"). This can cause problems when the goal is to count or process blank cells that include empty strings. One workaround is to use the LEN function to test for a length of zero. For example, the formula below will return TRUE if A1 is empty or contains a formula that returns an empty string: So, inside the IF function, you can use LEN like this: You can use this same approach to count cells that are not blank.

Dave Bruns

Hi - I’m Dave Bruns, and I run Exceljet with my wife, Lisa. Our goal is to help you work faster in Excel. We create short videos, and clear examples of formulas, functions, pivot tables, conditional formatting, and charts.