ISERROR

Check if a cell contains any Excel error value with the ISERROR function.

Information
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Excel All versions
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Google Sheets Supported

Spreadsheet editor

Syntax

=ISERROR(value) Returns: Boolean

Arguments

Argument Required Description
value Yes The value or expression to check for an error.

About

ISERROR tests whether a cell or value contains any error type. It returns TRUE when it finds an error (#N/A, #VALUE!, #REF!, #DIV/0!, #NUM!, #NAME?, or #NULL!) and FALSE for everything else.

Use ISERROR when you need to detect formula errors before they break your calculations. It's helpful for building error-resistant formulas, cleaning up imported data, or identifying problem areas in large spreadsheets. Combine it with IF to handle errors gracefully, or use IFERROR as a shortcut when you want to replace errors with specific values.

ISERROR catches all error types, making it comprehensive but sometimes too broad. If you only care about #N/A errors, try IFNA instead. For error types other than #N/A, consider ISERR.

Examples

Detecting different error types

See how ISERROR catches all error types - #DIV/0!, #VALUE!, #REF!, and more. Try editing the formulas in column B and watch ISERROR detect each error. Notice it returns FALSE for valid numbers and text.

Spreadsheet editor

Empty cells aren't errors

Watch how ISERROR returns FALSE for empty cells. This is a common gotcha - blank cells aren't errors. See column D for how to detect both errors and blanks using OR with ISBLANK.

Spreadsheet editor

Counting valid calculations for data quality

Use ISERROR with SUMPRODUCT to count how many calculations succeeded. Change the expenses in column C (try entering text) and watch the count update. Perfect for auditing your data.

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Watch out for

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ISERROR catches all errors, even ones you want to see

Using ISERROR to hide all errors might mask legitimate issues like broken cell references (#REF!) or incorrect formulas (#NAME?). You lose visibility into what's actually wrong.

→ Consider using IFERROR with specific replacement values, or use ISERR to exclude #N/A errors (which are often expected). Check error types with ERROR.TYPE when you need more control.

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Duplicating complex formulas makes updates difficult

Writing =IF(ISERROR(VLOOKUP(...)), 'Error', VLOOKUP(...)) repeats the VLOOKUP twice. If you need to update the formula later, you have to change it in two places.

→ Use IFERROR instead: =IFERROR(VLOOKUP(...), 'Error'). It's cleaner and only calculates once. Or use a helper column to store the VLOOKUP result first.

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ISERROR returns FALSE for empty cells

Empty cells aren't errors, so ISERROR returns FALSE for them. If you're trying to detect both errors and blanks, ISERROR alone won't work.

→ Combine with ISBLANK: =OR(ISERROR(A1), ISBLANK(A1)). Or check if the cell equals empty text: =OR(ISERROR(A1), A1="").

Tips & notes

ISERROR returns TRUE for all seven error types: #N/A, #VALUE!, #REF!, #DIV/0!, #NUM!, #NAME?, and #NULL!. The function tests values as they are and won't convert text to numbers or perform any calculations. For most error-handling situations, IFERROR provides a simpler alternative that combines checking and replacing in one function.

Common questions

What's the difference between ISERROR and ISERR?

ISERROR catches all error types including #N/A, while ISERR catches every error except #N/A. Use ISERR when #N/A is an expected result (like in VLOOKUP or MATCH) but other errors indicate real problems.

Should I use ISERROR or IFERROR?

Use IFERROR when you want to replace errors with a specific value. It's shorter and cleaner. Use ISERROR with IF when you need different logic for errors versus valid values, or when you need to check errors without replacing them.

Can ISERROR detect errors inside other functions?

Yes. ISERROR evaluates whatever you give it, so =ISERROR(VLOOKUP(...)) will return TRUE if the VLOOKUP generates an error. The error doesn't need to already exist in a cell.

Does ISERROR slow down my spreadsheet?

ISERROR itself is fast, but if you're using it with complex formulas that you duplicate (like in IF statements), you're calculating those formulas twice. Use IFERROR or helper columns for better performance in large sheets.