Are cellphones ever truly off?

Yes, they do turn off, and no they do not have radiation, not in that sense anyways. When you turn a phone off it sends a signal to your service provider and that automatically sends calls to voicemail

Off is about as off as a powered-down computer; there is still a little power flowing to it’s equivalent of the motherboard, but they are not putting out a signal of any kind, so in that sense, they are off. Of course, “Airplane mode” also shuts down the radio.

If you are simply worried about minimizing the radiation from your cellphone for health reasons, rest assured that a smartphone is probably one of the less irradiating things you deal with in daily life though.

Cellphones generate signals in the 2 GHz range. It’s not high enough frequency to be ionizing radiation, which would be really bad. 2 GHz is what WiFi and microwave ovens also generate.

I have seen internet rumors that phone companies can listen in on your phone, even when it is off. That is as (not) factual as most internet rumors.

You can test a turned off phone by checking the battery level before and after a long time being “off”. I have always found it to be the same, thus no power was used while it was off.

My phone does not receive calls when switched off. My service provider sends all incoming calls to voicemail. That takes place on their servers, not on my phone.

If you take the battery out.

@jerv‘s description good that even when “off” there is a little bit going on, the phone is ready to respond to you pushing the power button. And it won’t be radiating any cellphone signal at that time.

@marinelife is correct it’s really really off only if you take out the battery.

Some (that I know of for sure, don’t know about all) have another hidden, micro battery hidden away so even if it is off, there is juice. I have seen one removed with no impact in function.

They are never truly off until you take the battery out