In Excel: use =ISBLANK(value) — it returns TRUE only for a truly empty cell, and FALSE for a formula that returns an empty string.
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Syntax
Arguments
| Argument | required / optional | Description |
|---|---|---|
value | required | The cell to test. Returns TRUE only for a genuinely empty cell. |
Related functions
Decide whether an empty-string formula result should count as blank — that choice picks the test.
For strict emptiness type =ISBLANK( and click the cell.
Wrap it in IF to turn TRUE and FALSE into a readable label.
For the looser test that also catches "" results, use =IF(A2="", …) instead.
What this does
ISBLANK tests whether a cell is genuinely empty. The distinction that trips everyone is the empty string: a cell holding =IF(A2="","",A2) looks blank but contains a formula, so ISBLANK returns FALSE for it. That is technically correct and practically infuriating, which is why the more robust emptiness test in most real workbooks is =A2="" — that treats both a truly empty cell and an empty-string result as blank. Use ISBLANK when the difference genuinely matters, such as distinguishing "not entered" from "calculated to nothing" on a form. Most people learn this as a sequence of clicks and forget it by next week; learning it as a pattern instead is what lets you apply it to the next, slightly different version of the problem without starting from scratch. That is the difference this page is trying to make. For “excel isblank function”, the reliable version is a short checking loop, not just the first command that appears to work. Run it on a deliberately small range first, watch how the affected blanks change, and only then apply the same setup to the full sheet. When a formula is involved, keep the inputs labelled beside it, reference cells instead of typing values, and apply number formatting only after the result checks out. That is what makes a calculation you can defend to a CFO or an auditor useful in real work: repeatable, auditable, and not dependent on memory or luck.
A worked example
Flagging unfilled required fields: =IF(ISBLANK(C2), "Missing", "OK") down a form column. On a column of =IF(...,"",...) formulas the same test returns "OK" everywhere, because those cells are not empty — switch to =IF(C2="", "Missing", "OK") to catch both cases. ISBLANK is the difference between "nobody filled this in" and "this calculated to nothing", which is exactly what a form validation needs to distinguish. Check the referenced cells, argument order and result type in your workbook. Start with the worked example before changing an input, then compare the changed result with the calculation you expected. An error value or a result of a different type is a reason to inspect the inputs and arguments.
In Google Sheets
Google Sheets support for this task has not been verified. Check the function, arguments and workflow in the target product before transferring the example. Matching formula notation does not establish identical behaviour. Keep this page bookmarked for the next time the same question comes up. Better still, repeat the steps once in your own workbook — doing it yourself is what turns a copied answer into something you remember. For “excel isblank function”, keep the input cells and the result visible while you check the formula in Excel. Follow the worked example and change one input at a time. The steps explain the workbook calculation; this page does not run a live calculator for that task.
Common mistakes
- Expecting TRUE from a formula that returns "" — the cell contains a formula and is not blank.
- Using
ISBLANKon a cell containing a single space, which is also not blank. - Reaching for
ISBLANKwhen=A2=""is the more forgiving test the situation actually needs.
Frequently asked questions
Why does ISBLANK return FALSE on an empty-looking cell?
The cell holds a formula that returns an empty string. It is not empty, so ISBLANK is correct — use =A2="" to treat both as blank.
How do I check if a cell is empty?
=ISBLANK(A2) for strict emptiness, or =A2="" for the looser test that also catches empty-string results.
How do I count empty cells?
COUNTBLANK, which — unlike ISBLANK — does count empty-string formula results as blank.