Hello Niloy, My name is Eric and I would be glad to answer this question for you today! 1. It is possible that sites on Firefox and DuckDuckGo are licensed under the Google Domain. Sites for example being YouTube (dot) com (A Google Product) or Weebly (dot) com (Not A Google Product however Google has part ownership alongside Stripe). In the case of Weebly, Google uses their stake in it to help stripe and content makers Sell Your Information to Advertisers. 2. There is always the possibility of Google tracking you weather you use a link of theirs, or see an Ad of theirs, or even visit a Non-Google Site. This is because Google LLC (Alphabet) is located in the United States and is protected under the 1st amendment allowing them to do so. It is a lot like police, feds, and the President knowing what your IP or search history is without you knowing. Thats why we always suggest using a VPN or Tor (or both) connection alongside Firefox. Though, that doesnt shut sites and the government out completely. Summary: Google can most likely still track you even on another web browser or search provider. There is even a DRM (Digital Rights Managent) Add-On installed on Firefox owned by Google at start. However there are some additional steps you can take to limit Google from this access: 1. Use a VPN (Makes you Anonymous) 2. Use AdBlocker (Or AdBlockPlus) to disable Ads (mostly ones from Scammers and Google) 3. Always choose Firefox as your prefered browser 4. Dont visit any Google Sites! Including YouTube 5. Since your on Android, get apps from APK sources NOT Google Play Store (A Google Tracking Store) Hope this helps, sorry for the lengthy reply. Best Regards, -Eric