> ## Documentation Index
> Fetch the complete documentation index at: https://docs.less.tech/llms.txt
> Use this file to discover all available pages before exploring further.

# Unique

> Remove duplicate rows

The Unique tool enables you select one or several columns that should be unique whereby all the duplicate rows are removed.

<Warning>
  The Unique tool keeps the first rows that is unique and discards all the
  following duplicates
</Warning>

The Filter tool outputs two anchors. That means you can easily access the rows that pass through the filter and the rows that don't.

<Frame>
  <img src="https://mintcdn.com/less-51/tvKC10PJfN6EkkU2/images/tools/unique/Anchors.gif?s=3fa45f70163f5c9b33141b2b465e3ec9" width="2000" height="1251" data-path="images/tools/unique/Anchors.gif" />
</Frame>

Note that when you select multiple columns, you create column pairs behind the scenes - almost like combining the two (or more) columns into a new column. If you dataset looks like this:

| amount | text        |
| ------ | ----------- |
| 100    | Hello       |
| 200    | World       |
| 300    | World       |
| 200    | Hello World |
| 100    | hello world |

There are then three possible options and output:

1. **amount** should be unique which outputs the first three rows
2. **text** should be unique which outputs the first two rows and last two rows
3. **amount** and **text** should be unique which outputs all five rows

### Configuration

<Steps>
  <Step title="Select unique columns" stepNumber={1} titleSize="p">
    Select the column(s) you would like to be unique. You can select one or
    many.

    <Note>
      The order in which you select multiple columns does not matter for the
      Unique tool
    </Note>

    <Note>
      The Unique tool is case sensitive meaning *This* and *this* are two
      different and unique values
    </Note>
  </Step>
</Steps>