Guide to Excel's ISBLANK Function

Find out if cells are blank with the ISBLANK function

Find Empty or Blank Cells with Excel's ISBLANK Function

The ISBLANK function is one of Excel’s IS functions or “Information Functions” that can be used to find out information about a specific cell in a worksheet or workbook.

As the name suggests, the ISBLANK function will check to see if a cell does or does not contain data.

Like all of the information functions, ISBLANK will only ever return an answer of TRUE or FALSE:

  • If the cell is empty, ISBLANK returns a value of TRUE — row two in the image above
  • If the cell is not empty, the function returns the value of FALSE — rows three to 10 above.

Normally, if data is later added to an empty cell the function will automatically update and return a FALSE value.

The ISBLANK Function Syntax and Arguments

A function's syntax refers to the layout of the function and includes the function's name, brackets, and arguments.

The syntax for the ISBLANK function is:

= ISBLANK ( Value )

Value — (required) usually refers to the cell reference or named range (row five above) of the cell being tested.

Data in a cell that will cause the function to return a value of TRUE includes:

  • numbers — row three
  • text strings — rows four and five
  • Boolean or logical values — row six
  • error values — row seven
  • non-printing characters — row eight
  • regular spaces — row nine
  • non-breaking spaces — row 10

Example Using Excel's ISBLANK Function:

This example covers the steps used to enter the ISBLANK function into cell B2 in the image above.

Options for entering the ISBLANK function include manually typing in the entire function =ISBLANK(A2), or using the function's dialog box — as outlined below.

Entering the ISBLANK Function

  1. Click on cell B2 to make it the active cell
  2. Click on the Formulas tab of the ribbon
  3. Choose More Functions > Information to open the function drop-down list
  4. Click on ISBLANK in the list to bring up that function's dialog box
  5. Click on cell A2 in the worksheet to enter the cell reference into the dialog box
  6. Click OK to complete the function and close the dialog box
  7. The value TRUE should appear in cell B2 since cell A2 is empty
  8. When you click on cell B2 the complete function = ISBLANK (A2) appears in the formula bar above the worksheet

Invisible Characters and ISBLANK

In the image above, the ISBLANK functions in cells B9 and B10 return a FALSE value even though cells A9 and A10 appear to be empty.

FALSE is returned because cells A9 and A10 contain characters that are invisible:

  • row nine contains regular space characters (entered using the spacebar on the keyboard)
  • row 10 contains non-breaking spaces

Non-breaking spaces are one of a number of control characters commonly used in web pages and these characters sometimes end up in a worksheet along with data copied from the web page.

Removing Invisible Characters

Removing both regular and non-breaking space characters can usually be accomplished using the Delete key on the keyboard.

However, if a cell contains good data as well as non-breaking spaces, it is possible to strip the non-breaking spaces from the data.