Filter syntax extensions

uBlock supports most of Adblock Plus filter syntax. However uBlock does not support some very specific cases, and also added its own extensions to ABP filter syntax.

Not supported

document for exception filters (those prefixed with @@):

Not supported. The purpose of the document option is to disable uBlock completely. The reason it is not supported is to be sure that users explicitly disable uBlock themselves if they wish (through whitelisting), not having some external filter list decide for them.

Extended syntax

uBlock extends Adblock Plus filter syntax.

Network filters

document for block filters:

This will cause web pages which match the filter to be subjected to strict blocking.

first-party:

This is equivalent to ~third-party. Provided strictly for convenience (0.9.9.0).

important:

The filter option important means to ignore all exception filters (those prefixed with @@).

It applies only to network block filters. The important option will allow you to block with 100% certainty specific network requests.

Example: ||google-analytics.com^$important,third-party will block all network requests to google-analytics.com, disregarding any existing network exception filters. Another example: ||twitter.com^$important,third-party. Etc.

inline-script:

To specifically disable inline script tags in a main page: ||example.com^$inline-script.

Cosmetic filters

Entity-based cosmetic filters: Filters which are to be applied to a specific entity.

An entity is defined as follow: a formal domain name with the Public Suffix part replaced by a wildcard.

Examples: google.* will apply to all similar Google domain names: google.com, google.com.br, google.ca, google.co.uk, etc. Another example: facebook.* will apply to all similar Facebook domain names: facebook.com, facebook.net.

Since the base domain name is used to derive the "entity", google.evil.biz would not match google.*.