# Why does ISBLANK return FALSE for a cell that looks empty?

The cell holds a formula returning "" or a space. Test what it shows instead: =IF(LEN(TRIM(B2))=0,"Empty","Has data").

**Excel:** `=IF(LEN(TRIM(B2))=0,"Empty","Has data")` (Every current version)

**Google Sheets:** the same formula works.

## Example

Sample data (row 1 is the header):

| A | B | C |
| --- | --- | --- |
| What is in B | Value | Check |
| Nothing |  |  |
| A formula returning "" | ="" |  |
| A single space |  |  |
| Zero | 0 |  |
| A dash | - |  |

Formula in C2, filled to C6: `=IF(LEN(TRIM(B2))=0,"Empty","Has data")`

Result: Empty; Empty; Empty; Has data; Has data

## How it works

ISBLANK is TRUE only for a cell with nothing in it at all: no value and no formula. A formula that returns "" and a cell with a space look empty but aren't, so ISBLANK says FALSE. `LEN(TRIM(B2))=0` checks what the cell shows: after removing spaces, is anything left?

## Other ways

- `=IF(B2="","Empty","Has data")`: ="" treats an empty cell and a formula returning "" as empty, but not a space. (The single-space cell shows "Has data".)
- `=IF(ISBLANK(B2),"Empty","Has data")`: ISBLANK is TRUE only for a cell with nothing in it. (The "" formula and the space both show "Has data".)

## Common mistakes

- A 0 isn't empty, even when a number format hides it.
- Text pasted from web pages can contain non-breaking spaces that TRIM leaves behind. Remove them with `SUBSTITUTE(B2,CHAR(160),"")`.

## Questions

**Can a formula return a truly empty cell?**

No. A formula always returns something; return "" and test with ="" or LEN.

**Does Google Sheets behave the same?**

Yes: ISBLANK is FALSE there too for a formula that returns "".

Every formula and result on this page was checked by running it in the Spreadsheet Practice formula engine on 2026-10-30.

Source: https://spreadsheetpractice.com/formulas/isblank-false-for-empty-looking-cell