Number of unsolicited connections made by web browsers on first start: https://sizeof.cat/post/web-browser-telemetry-2025-edition/

#Firefox is worse than Chrome or Safari :(

Librewolf is slightly better. Vivaldi is lower than Chrome, Firefox and Librewolf.

Winners with zero connections are: Ungoogled Chromium, Kagi Orion, Tor Browser and Pale Moon.