Note: it’s important that CF formulas be entered relative to the “active cell” in the selection, which is assumed to be B4 in this case. Once you save the rule, you’ll see the formatting applied to all empty cells.

### Empty vs. blank

The ISBLANK function only returns TRUE when cell are actually empty. If a cell contains a formula that returns an empty string ("") ISBLANK won’t see these cells as blank, and won’t return true, so they won’t be highlighted. In this way, ISBLANK would be better thought of as “ISEMPTY” (Hat tip, Mike Girvin). If you want to highlight cells that are blank and cells that just appear blank, you can use this formula instead: The LEN function returns the length of text as a number. A cell that contains an empty string ("") will also have a length of zero, so the formula will TRUE for both “blank” and “empty” cells.

### Not blank

To conditionally format cells that are not blank, you can use a formula like this: The NOT function reverses the logic.

### 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.