Through which application can I track the data that the phone sends?

Question

Android

I heard that with the help of some applications it is possible to track the data that the phone sends and where, so you can understand whether the phone sends personal data to intruders.

Answer 1

As for applications, these are called packet sniffers. In the open spaces w3bsit3-dns.com you can find Packet Capture and HTTPCanary on request. But you are unlikely to see directly open decrypted traffic “in text form” there.
Another question - is it necessary? Now it is very difficult to find such an application that it directly steals everything. If you are worried about your data, then I will upset you, you are a little late. Although they are not intruders, but almost all the social networks that you use and the search giants already know a lot about you. What are the GDPR archives of VKontakte and the page with Google advertising preferences worth.
And the best way to check if anything is being sent to intruders is to give the phone to someone close who knows more than you and ask if you have any bullshit installed.
PS If you are paranoid - deny access to the Internet to applications that you do not trust. As a bonus, you can also take away the rights to the storage, so that they stop working altogether.