iPhone SE (2016) Playing music with no SIM card or WiFi

[Crystal21]

Last week when I had my iPhone 12 mini (now being returned) I was out driving and used my old SE for music, since it still has a headphone socket and my car has no Bluetooth. As I set off, I remembered that the SE has no SIM card and obviously no WiFi when I’m driving so I expected the music to quit as soon as I drove away from the house. It didn’t. It kept playing for the full 30 mins. The area I was driving in for most of that has no phone reception. There’s only one network that gets any signal, and it’s not mine. The SE was not tethered to the 12 mini. All the music is streamed. I have no songs at all downloaded onto my phone (Either phone).

What sort of wizardry is this? How is it possible for music to be streamed with no internet at all? I can post a screenshot of Spotify playing, clearing showing it has no WiFi or SIM card.

 

[now i see it]

Music is buffered as i it is downloading. Extra data gets downloaded while streaming.
Then when disconnected from network it continues playing from the buffer cache until it’s all gone.

 

[Crystal21]

Music is buffered as i it is downloading. Extra data gets downloaded while streaming.
Then when disconnected from network it continues playing from the buffer cache until it’s all gone.

I don’t really understand any of that but does it mean that I can continue streaming music without any sim/WiFi? How long does the ‘buffer cache’ last?

 

[now i see it]

Technically you’re not streaming anymore when you disconnect from your network. You’re playing the remaining music that’s already downloaded that’s been stored on your device. How long it will play depends on your network speed while you were connected (how much data got downloaded) and the bit rate of the music- which you’ll never really know.
It’ll probably play about as long as it did the last time. Experiment and find out.