# Rules Presets

The **Rules** functionality in Fiddler Everywhere is a powerful tool for tackling various web debugging tasks. The Fiddler team created rules presets (predefined rules) that you can use directly or with minimal adjustments to fit your test cases.

> tip A rule in Fiddler contains a **matching condition** (or set of conditions) that determines the target HTTP sessions and an **action** (or set of actions) that applies to them.

The rules presets were conditionally separated into the following groups:

* Tooling—A set of rules that enables you to change different behaviors in the client or server. For example:
  * [Bypassing CORS](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/tooling/bypass-cors)
  * [Blocking cookies](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/tooling/blocking-cookies)
  * [Disabling the browser's cache](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/tooling/disabling-cache)
  * [Changing user-agent](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/tooling/changing-user-agent)
* Filters—A set of rules demonstrating how to show or hide targeted traffic. For example:
  * [Showing only localhost traffic](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/filters/show-only-localhost-traffic)
  * [Showing only traffic from specific hosts](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/filters/show-only-traffic-from-specific-host)
  * [Hiding traffic from specific hosts](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/filters/hide-traffic-from-specific-hosts)
  * [Showing traffic only from specific processes](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/filters/show-only-traffic-from-specific-processes)
  * [Hiding traffic from specific processes](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/filters/hide-traffic-from-specific-processes)
  * [Hiding CONNECT tunnels](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/filters/hide-connect-tunnels)
* Block lists and Allow lists—A set of rules demonstrating how to block or allow target traffic. For example:
  * [Blocking traffic to specific hosts](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/block-and-allow-lists/block-traffic-to-specific-hosts)
  * [Allowing traffic only to specific hosts](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/block-and-allow-lists/allow-traffic-only-to-specific-hosts)
  * [Blocking traffic from specific processes](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/block-and-allow-lists/allow-traffic-only-from-specific-processes)
  * [Allowing traffic only to specific processes](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/block-and-allow-lists/block-traffic-from-specific-processes)
* Map Traffic—A set of rules that demonstrates how to redirect traffic and to mock HTTP requests and responses. For example:
  * [Mapping to remote URLs](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/map-traffic/map-remote)
  * [Mapping to localhost addresses](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/map-traffic/map-localhost)
  * [Mapping to a local file](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/map-traffic/map-file)
  * [Mapping to a manually created response](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/map-traffic/map-manual)
  * [Creating a temporary 307 redirect](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/map-traffic/temporary-redirect)
* Modify Traffic—A set of rules demonstrating how to make custom modifications to sent HTTP requests and received HTTP responses. For example:
  * [Modifying the content of a response body](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/modify-traffic/modify-reponse-body)
  * [Modifying image URLs](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/modify-traffic/modify-image-url)
* UI Modifications—A set of rules demonstrating how to change the Fiddler UI to fit your needs. For example:
  * [Highlighting long-living sessions](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/ui-modifications/mark-long-living-sessions)
  * [Highlighting sessions that contain JavaScript or JSON](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/rules-presets/ui-modifications/mark-scripts-and-jsons)

All rules presets are available as FARX files (Fiddler uses the FARX format to export and import a rule or set of rules) in
<a href="https://github.com/telerik/fiddler-everywhere/tree/master/rules" target="_blank">the public GitHub repository of Fiddler Everywhere</a>.

The above rules are also available in Fiddler Everywhere through a group called **Default Templates**.

![the "Default Templates" group in Fiddler Everywhere](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/assets/c88183bcea4ea4662dd3c848079e5626/default-templates.png)

## See Also

* [Learn more about the Rules functionality in Fiddler Everywhere here...](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/modify-and-filter-traffic/modify-traffic-with-rules)
* [Learn how to use the Rules preset here...](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/knowledge-base/how-to-use-the-rules-presets)
* [Learn how to organize and set the order of execution of multiple rules here...](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/modify-and-filter-traffic/organizing-rules)
* [Learn how to use the Fiddler breakpoints to pause, debug, and modify HTTPS traffic on the fly](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/modify-and-filter-traffic/breakpoints)
* [Understanding the Matching Conditions and the Actions](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/modify-and-filter-traffic/conditions-and-actions#conditions)
* [Understanding the role of Final and Non-Final Actions](https://www.telerik.com/fiddler/fiddler-everywhere/documentation/modify-and-filter-traffic/conditions-and-actions#final-and-non-final-actions)