Lesson 7 of 7 · 3 min read
Chrome, Firefox and the other browsers
Every browser now has its own view on tracking. You do not need to know the details, but you should know who does what, because your clients’ visitors use all of them.
- Collect
- Store
- Use
- Activate
Chrome
Chrome, the most used browser, still allows third-party cookies by default. Google had planned to phase them out for years and in 2025 decided to keep them. Chrome is the most permissive of the big browsers, but users can still block cookies themselves, and ad blockers work in Chrome too.
Firefox
Firefox blocks known trackers by default with Enhanced Tracking Protection and keeps each website’s cookies in their own box, so they cannot follow a visitor from site to site.
Brave, Edge and ad blockers
Brave blocks trackers and ads out of the box. Edge has its own tracking prevention, set to balanced by default. And on any browser, an ad blocker can remove tags entirely.
What this means
The share of data lost depends on the client’s audience: a B2B audience on company laptops behaves differently from a young audience on iPhones. Server-side and server-to-server routes are what make the result less dependent on the browser mix.
Key takeaways
- Chrome still allows third-party cookies; Safari and Firefox limit tracking by default.
- Ad blockers affect every browser.
- The loss depends on the client’s audience, so check their browser split.
For your marketing agency
Look at a client’s browser and device split before you promise anything. It tells you how much they lose today and how much better tracking can win back.