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

# Regular expressions

> Use regular expressions to target URLs with precise pattern matching in Kameleoon targeting conditions.

Kameleoon lets you target URLs using regular expressions.

Here is a detailed list of the most used regular expressions:

* `.` = Replace one character with another in your regular expression. For example, the expression `Kamele.on` will target URLs containing `Kameleoon`, `Kamele0n`, `Kamele8on`, etc.
* `*` = Delete the previous character or add the same character after. For example, the expression `Kameleoo*n`, will target URLs containing `Kameleon`, `Kameleoon`, `Kameleooon`, etc.
* `?` = Delete or leave the previous character. For example, `Kameleoo?n` will target URLs containing `Kameleon` and `Kameleoon`.
* `+` = Add the previous character once or several times. For example, `Kameleo+n` will target URLs containing `Kameleoon` and `Kameleoooon`.
* `|` = Target several chains of characters. It is like an "Or" operator. For example, `Kameleoon|Chameleoon` will target `Kameleoon` or `Chameleoon`.
* `^` = Targets the chain's beginning. `^Kameleoon` will target URLs starting with `Kameleoon`.
* `$` = Targets the chain's end. `Kameleoon$` will target URLs ending with `Kameleoon`.
* `()` = Creates groups of several elements. This regular expression is usually combined with `|`. For example, `Kameleoon (AB Testing|Conversion) Tool` will target `Kameleoon AB Testing Tool` or `Kameleoon Conversion Tool`.
* `[]` = Will target each character inside the `[]`. For example, `/Kameleoon/[234]` will target `Kameleoon 2`, `Kameleoon 3` and `Kameleoon 4`.
* `-` = `/kameleoon/[2-9]` will target every page from `Kameleoon 2` to `Kameleoon 9`.
* `{}` = Defines character instance limits. For example, `Kameleo{2,4}n` will target URLs containing `Kameleoon`, `Kameleooon`, or `Kameleoooon`.

<Note>
  If your character chain contains a special character (for example, `,`, `.`, `*`), add a backslash \ before it.
</Note>

<Note>
  These expressions are case-sensitive.
</Note>

Here are some examples of regular expressions:

* `^.{10}$` = targets URLs containing exactly 10 characters.
* `general\.(html|php)$` = targets URLs ending with either `general.php` or `general.html`.
* `/fr/` = targets URLs containing `/fr/`.
* `/annexes/.*d{3}` = targets URLs containing the fragment `/annexes/` and a three-digit number.
* `/annexes/.*d{2}.*test.html$` = targets URLs containing the fragment `/annexes/`, a two-digit number, and ending with `test.html`.