> For the complete documentation index, see [llms.txt](https://docs.cascade.io/cascade/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.cascade.io/cascade/functions-and-expressions/functions/logical/isunique.md).

# ISUNIQUE

ISUNIQUE( `series` )

Returns a boolean sereis indicating whether each value of the specified series is unique.

### Arguments

| Argument | Description                          |
| -------- | ------------------------------------ |
| `series` | Series of which to assess uniqueness |

### Output

Outputs true if the value is unique and false if the value is a duplicate.

### Example

{% embed url="<https://datawrapper.dwcdn.net/DQNel/1>" %}