There is no clear indication of bias, from PrivacyTests, just accusations.
If the tools and tests ARE open source (which they are), they can be checked for bias/cheating. Someone could also expand (fork) upon them to give more of a rounded opinion.
A better defense against accusations of bias is a group or persons transparency.
Simply having an open source methodology and code base isn’t transparency either, since it takes a much, much deeper and more developed skill set to audit both software source code and testing methodology than it takes to raise an eyebrow at sus circumstances.
It’s still unfinished, but he’s working on a tool for you to test your own browser. You can do so here:
https://privacytests.org/me.html
It’s the exact same tests he runs, that are open source. Everything can be found, (if you don’t trust the guy) on his GitHub:
https://github.com/privacytests/privacytests.org/tree/master/scripts
You can have open source software with a bias towards something.
You can but:
A better defense against accusations of bias is a group or persons transparency.
Simply having an open source methodology and code base isn’t transparency either, since it takes a much, much deeper and more developed skill set to audit both software source code and testing methodology than it takes to raise an eyebrow at sus circumstances.