Which browsers block 3rd party cookies by default?

Question

I want to have a feeling which percentage of our traffic does not support third party cookies. For this I need to now Which browsers / OS combinations currently block 3rd party cookies by default. Does anybody know?

Answer 1

Currently, in mid-2018, the following browsers block third party cookies by default:

• Safari
• Firefox

As far as I can tell, no other browsers block third party cookies by default otherwise, although all browsers offer an easy option to enable it.

Also to be considered: Many AdBlockers and other extensions in browsers block third party cookies, like Adblock Plus, uBlock Origin, uMatrix, and many more. You can therefore assume quite a lot of people will block them, and they will only increase over time, as more people use ad and tracking blockers - and maybe more browsers will block third party cookies by default in the future.

It depends a lot on the country you are interested in to determine percentage-wise the number of people who block third party cookies. In some countries it easily exceeds 50%.