Yes, walkie talkies work with zero cell service and zero WiFi, that’s the entire point of them.
Short answer: do walkie talkies work without cell service? Yes. Do walkie talkies work without wifi? Also yes. They use radio frequencies, not the internet. Two radios talk directly to each other, so there’s no tower in the middle that can go down.
Here’s the catch nobody leads with: do walkie talkies need signal? They need radio signal, but they don’t need infrastructure signal. Your phone is useless in a dead zone. A pair of walkie talkies in that same spot works fine, as long as they’re in range of each other.
The one exception is the new generation of smart radios that route voice over cellular data, the Zello-style units in the zello category. Those do need a network. To be fair, those aren’t really walkie talkies in the classic sense, they’re phones with a PTT button.
For true off-grid comms, check the range expectations first, our range test is brutally honest about it. And the two-way radio selection category only lists units that work tower-free. That’s a promise we actually keep.