🔗 Browser telemetry - 2025 edition

Charts

*number of connections for 2025 and 2021, for each browser tested. some of the web browsers weren’t tested in 2021 but they are now.



Web Browser telemetry - 2025 edition - sizeof(cat)

https://sizeof.cat/post/web-browser-telemetry-2025-edition

All web browsers tested are the latest versions available today, test device is a MacBook M1 laptop (so macOS Sonoma, but the results should be similar regardless of the operating system) with a clean profile, all network connections blocked, application-level network connection whitelisting and only Little Snitch installed. So it’s actually Little Snitch that does all the heavy-lifting, I’m just the robot that is parsing the data.

All network traffic is routed through a VPN in Japan.

I am shocked by Zen, Floorp, Edge. Unsurprised by chrome, although looking at the urls it talks to, it's not super bad - it's phishing site data etc. Safari is low, but still more than I expected and Kagi's Orion and Tor Browser truly take the win with ZERO.