# Functions

<a id="istestchain"></a>

##  isTestChain

▸ **isTestChain**(chain?: *`string` \| `null`*): `boolean`

*Defined in [isTestChain.ts:7](https://github.com/polkadot-js/ui/blob/0dbdc7e/packages/ui-util/src/isTestChain.ts#L7)*

**Parameters:**

| Name | Type |
| ------ | ------ |
| `Optional` chain | `string` \| `null` |

**Returns:** `boolean`

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