Filters

iCab Mobile offers filters to block advertising or tracking code in websites, for example. Ready-made popular filter lists are offered, which you can simply activate, but you can also create filters manually according to your own requirements. All of this can be defined in the settings under Filters.

User-defined filters

User-defined filters are organized in groups (folders). You can create any number of groups and save any number of filters in each group. You can activate or deactivate groups as a whole, but you can also activate or deactivate individual filters. Usually you should save filters that have the same task in the same group (e.g. a group for blocking advertising banners, a group for blocking tracking code, possibly other groups for special tasks, etc.).

Within a group, you can create new filters using the Add filter button or the icon in the bar at the top. Using the Third-party resources button, you can also call up a list of all resources that have been loaded on the current website but do not originate from the main domain of the site. Advertising or tracking code that is worth blocking is most likely to be found there. By tapping on one of these entries, a new filter entry is also created directly, pre-filled with the data of the selected resource, so that you only have to adjust it slightly if necessary.
Attention: resources from other domains are not always unimportant for the functioning of the site, not everything is advertising or tracking. When creating your own filters, you should therefore always check whether these filters do what you expect them to do.

A filter has several components that define which resource is to be blocked:

Components	Description
Filter	This defines the URL(s) of the resources that are captured by the filter. Wildcards can be used to capture several resources at once (a simplified version of regular expressions is used here)
Action	Defines what the filter should do: Block resource: Blocks the addressed resource Block cookies: Blocks the cookies that are set by the resource Hide page element: Hides elements of the page. This is done using CSS, which is why you have to specify a CSS selector that defines the elements to be hidden Ignore previous filters: This action can be used to define exceptions. If the resource is blocked by other (somewhat broader) filters, this action can override these other filters. The order of the filters is important here. Only filters in the same group that are listed before this filter can be deactivated. Convert HTTP to HTTPS: ensures that resources loaded unencrypted via HTTP are loaded encrypted via HTTPS instead.
Source	1st party means that only resources from the same domain as the main page are recorded; 3rd party means that only resources from other domains are recorded. Everything includes all resources.
Context	The context defines whether the resource must be integrated directly in the main document (parent frame) or only in an integrated document (child frame).
File Types	The file types are used to specify which type of documents are to be covered by the filter rule
Restrictions	The restrictions can be used to define additional conditions regarding the address of the main document and the domain of the resource

The Move filter to group option allows you to move the filter directly to another group, for example if it is sorted incorrectly.

Standard filter lists

The standard filter lists are popular filter lists that are also used for ad blocker extensions of many desktop browsers. These lists are created and managed by a large community. These filter lists are listed under Install standard filter lists, along with a brief explanation of what exactly they filter. By selecting a list, it is loaded and installed from the corresponding website. These filter lists are usually also updated automatically on a regular basis. If you open one of these already loaded filter lists, you can also change the update interval (the default setting is always the interval suggested by the list itself). Further information about the list is also displayed.

Using the button Install filter lists from website you can also install filter lists from other sources via their address (URL), or open some websites that offer these popular lists.

iCab Mobile supports all filter lists that are compatible with the Ad Block Plus, Easylist and uBlock lists, as well as normal “hosts” files.

Exceptions

It can also happen that filters block too much (overblocking) because, for example, a website has named files in the same way as many other sites have named advertising banners, and the filter therefore also blocks important page components. Other pages do not deliver any content as long as they recognize an advertiser blocker (i.e. advertising banners are filtered out). To avoid having to switch the filter off and on again every time you visit these sites, you can define exception rules for certain websites. Certain websites can thus be loaded completely unfiltered without any filters being activated. However, you can also easily block entire websites completely.

These exceptions are organized into groups for a better overview, which can be activated/deactivated individually.

An exception rule consists of an action (block website completely or ignore all filters) and a filter that defines the URLs that are affected by the exception rule. Wildcards such as * (stands for any number of characters), ? (stands for one character) and [abc] (stands for one character from the list in brackets) can be used.
Example: *[/.]icab.de/* would include the complete iCab website (incl. subdomains and subfolders).