mai-cliqz / blockrz

Build yourself an adblocker in less than 100 lines of TypeScript

Blockrz

Build yourself an adblocker in less than 100 lines of TypeScript! This is a minimal WebExtension doing adblocking/antitracking using most popular block-lists. It is meant as a very thin wrapper around the adblocker library which does most of the heavy-lifting. The code is also heavily commented and aims at explaining how a modern content-blocker works. This is a didactic project and contributions to improve it are more than welcome.

Building

1. Build the extension: npm ci && npm run bundle
2. Load it in Firefox or Chromium by using the "Load unpacked extension" feature

FAQ

Is it really less than 100 lines of code?

Yes.

$ loc content-script.ts background.ts

--------------------------------------------------------------------------------
 Language             Files        Lines        Blank      Comment         Code
--------------------------------------------------------------------------------
 TypeScript               2          143           15           70           58
--------------------------------------------------------------------------------
 Total                    2          143           15           70           58
--------------------------------------------------------------------------------

It's tiny, does it actually perform like other blocker extensions?

Yes it is small, but it leverages @cliqz/adblocker to do the heavy-lifting. This means that the extension is doing as much as any other content-blocker (if you make abstraction of the UI, of course, which only consists in a counter of blocked requests). At the time of this writing, this is still the fastest and most memory efficient adblocker around.

Which filters lists is it using?

Currently, it is using a pre-built engine distributed on Cliqz' CDN. This means that no parsing is required client-side to load the engine (super-fast loading cached between sessions!). The default lists at the time of this writing are:

• EasyList
• EasyPrivacy
• Peter Lowe’s Ad and tracking server list
• Adblock Warning Removal List
• uBlock filters
• uBlock filters - Privacy
• uBlock filters - Resource abuse
• uBlock filters - Badware risks
• uBlock filters - Unbreak
• Cliqz and WhoTracks.me custom filters