DAX function
ISBLANK — DAX function reference
Test for blank.
Syntax
dax
ISBLANK(<value>)
Examples
dax
ISBLANK([Sales])
→ true / false
dax
IF(ISBLANK(Sales[ShipDate]), "Not shipped", "Shipped")
→ A shipment-status label
dax
COUNTROWS(FILTER(Sales, ISBLANK(Sales[DiscountCode])))
→ Count of orders with no discount code applied
Common mistakes & gotchas
- ISBLANK(0) and ISBLANK("") both return FALSE — zero and empty string are not blank in DAX, only a genuinely missing value or an expression that evaluates to BLANK() is.
- BLANK() participates specially in arithmetic (BLANK() + 5 = 5, BLANK() * 5 = BLANK()) and in comparisons, which is why checking ISBLANK() explicitly is often clearer than relying on how a downstream calculation happens to treat a blank.
Related DAX functions
From Logical & error handling