Does anyone know of a tool to see what data is sent to 3rd parties
I remember a tool from years ago that would analyze what data a website was sending to 3rd parties. Does anyone remember what it was called or know of something similar.
There are lots of ways to do that. You can look at the developer tools provided by your browser. You can also run your browser through an intercepting proxy like burp or zap. The latter gives you the ability to intercept and step over actions, so you can really slow things down. I'd recommend using on of them.
The manual option is using ghostery and clicking in to each pixel URL to look at the paramaters. Many times the data is not obfuscated (in a facebook pixel you can see things like val=Ford, when you're browsing a page for a Ford truck)