> For the complete documentation index, see [llms.txt](https://sevenval.gitbook.io/flat/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sevenval.gitbook.io/flat/reference/functions/tolower.md).

# tolower()

```
string tolower([string|node-set argument])
```

The `tolower` XPath function returns the lowercase equivalent of the Unicode representation of the argument. If no argument is given, the value of the current context node is used. As usual, parameters of type [`node-set`](http://www.w3.org/TR/xpath/#node-sets) are automatically cast to `string`. Parameters of other types, e.g. `number` or `boolean`, are not accepted.