---
name: "up.util.isUndefined"
area: "API"
kind: "JavaScript function"
parent: "up.util module"
url: "https://unpoly.com/api/up.util.isUndefined"
---
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# up.util.isUndefined(value)

Returns whether the given argument is `undefined`.

---

## Parameters {#parameters}

### value {#value}

(required)

Type: any

---

## Return value {#return-value}

Type: boolean