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FunctionPedia
Quick Answer

ISBLANK Function

Tests whether a cell is truly empty.

✓ Excel✓ Google SheetsExcel All versions

Syntax

ISBLANK
(value)

Parameters

ParameterDescriptionRequired
valueThe cell reference to test (typically a single cell).Required

Basic Example

Check an empty cell

=ISBLANK(A1)
ResultTRUE

A1 contains nothing, so the function returns TRUE.

Advanced Examples

Example 1: A formula returning "" is NOT blank

A1 holds =IF(B1>0,B1,"").

Show the difference between empty and empty-string

=ISBLANK(A1)
Result: FALSE
Even though A1 displays blank, the formula returned "" which is text, so ISBLANK returns FALSE.

Example 2: A space is not blank

B2 contains a single space character.

Detect text that looks empty

=ISBLANK(B2)
Result: FALSE
A space is text, so the cell is not blank.

How ISBLANK Works

ISBLANK returns TRUE only when the referenced cell contains no value and no formula—not even a formula that returns an empty string. A formula that returns "" is still considered non-blank, as is a single space or any other character.

1
Pick the cell
Select the cell you want to test.
2
Enter the formula
Type =ISBLANK(cell).
3
Read the result
TRUE means truly empty, FALSE means it holds something.

Important Notes & Limitations

  • A formula returning "" is not considered blank.

  • A single space is text, not blank.

  • Tests one cell; for ranges wrap it in an array function like SUMPRODUCT.

Common Errors & Fixes

Thinks an empty string is blankA formula returned "".

Fix: Test with =A1="" or LEN(A1)=0 instead.

#VALUE! with a multi-cell rangeISBLANK expects a single reference.

Fix: Wrap it in SUMPRODUCT, e.g. =SUMPRODUCT(--ISBLANK(A1:A10)).

Download Practice File

Practice ISBLANK with Real Data

Download a sample CSV file with pre-populated data and practice exercises for the ISBLANK function. Works in both Excel and Google Sheets.

Works in Google SheetsCompatible with ExcelIncludes exercises

File format: CSV (comma-separated values) - opens in Excel, Google Sheets, and all spreadsheet apps

Frequently Asked Questions

Does ISBLANK detect a formula that returns ""?
No, only truly empty cells return TRUE; use =A1="" for an empty string.
Does a space count as blank?
No, a space is text, so ISBLANK returns FALSE.
How do I count blank cells including empty strings?
Use COUNTBLANK, which counts both truly empty cells and cells containing empty text.