If you really wanted to know, most of the tests for Brave's adblock engine are at https://github.com/brave/adblock-rust/tree/master/tests

Those are automated unit and integration tests with controlled filter data as inputs. That's the only practically useful kind of test for an adblocker.

They offer some testing sites at the bottom of the article: "Brave will continue to work with legitimate testing sites like https://privacytests.org and https://coveryourtracks.eff.org"

The article attacks the notion of acceptance testing on websites due to a nebulous fear that good != perfect and testing against the moving target of advertisements is too time consuming and potentially misleading, and instead suggests to test+rate adblockers based on a set of hand picked criteria that suits the product they're advertising. Unsurprisingly, half of the reasons are due to the advantages of adblock being first class native in their product vs a second class extension.

It sure isn't hard to be #1 in some category if you get to define it, but the comparison is kind of muddled for me when you consider the significant amount of time and effort towards maintaining and monetizing an entire platform of security vs maintaining an extension on an already popular platform. Harm reduction isn't a zero sum game.

Right, either release a better quality Adblock tester or stop whining? People need to test somehow.