[Macnertyu]

There’s a free way to check whether the data still on your iPhone. Just Google “Safewiper for iOS”, it’s not a totally free app, but the iPhone data checking function is free. Safe and useful.

it can erase everything from iPhone like contacts, photos, messages, apps, catch, call logs and more..

You can also try to restore your iPhone to factory resetting.

 

[Macnertyu]

There’s a free way to check whether the data still on your iPhone. Just Google “Safewiper for iOS”, it’s not a totally free app, but the iPhone data checking function is free. Safe and useful.

it can erase everything from iPhone like contacts, photos, messages, apps, catch, call logs and more..

source: https://www.safewiper.com/tutorials/erase-photos-from-iphone-before-selling.html

You can also try to restore your iPhone to factory resetting.