Browser extensions claiming to protect against fingerprinting will typically result in more data available for fingerprinting.

An interesting take on browser extensions which hope to prevent fingerprinting

With respect to native browser functionality:

Browser vendors have already invested a considerable amount of work into anti-fingerprinting. However, they usually limited themselves to measures which wouldn’t break existing websites…

And extensions:

Privacy protection extensions on the other hand aren’t showing as much concern. So they will typically do something like:

screen.width = 1280;
screen.height = 1024;

There you go, the website will now see the same display resolution for everybody, right? Well, that’s unless the website does this:

delete screen.width; delete screen.height;

And suddenly screen.width and screen.height are restored to their original values…