Free and Open Source Software

Use Fossify Dialer and block all unknown callers.

If you're in the US and on a carrier that supports stir/shaken and voLTE, Carrion can block (or silence) calls that fail verification. It can also block calls from a block list.

I use Yet Another Call Blocker. It has a custom block list you can use to block a specific number.

The block list also supports wildcard characters, which is my favorite feature! I use it to block swaths of numbers (much of my spam comes from the state I used to live in, so I block those area codes).

@Tucumano88 try Fossify Phone. It allows you to block numbers not in your contact list and private numbers as well.

And the name says it all: it's FOSS.

🔗 https://f-droid.org/packages/org.fossify.phone/

usually the built-in phone app will have an option to block calls from unidentified callers, no app needed.

A couple options here: https://github.com/offa/android-foss?tab=readme-ov-file#-call-blocker--spam-filter

None of them are very big but they may be worth a try

Been using NoPhoneSpam. While it won't automatically block any numbers, it will cancel incoming calls not matching its filters. Only issue is that, some times, it takes a few seconds for it to recognize not passing calls, but I think it happens when the phone is under a higher load and the system starts lagging a bit, like when downloading bigger files and playing games.