Android to Android
If you have an Android already, you probably also have a Google or a Gmail account, now the same thing—which will make this quite simple. If you don’t have a Gmail account, create one: you’ll need it to get the most out of your Android anyway. Once that is set up, go to “Settings” on your old Android phone, then “Accounts,” and select “Google.” This will give you a list of items to sync, including your calendar and Drive documents. Select “Contacts” and anything else you would like to transfer. Check “Sync Now,” and your data will be saved in Google’s servers.
Start your new Android phone; it will ask you for your Google account information. When you sign in, your Android will sync contacts and other data automatically. If you started using your phone before you established a Google account, go to “Accounts & Sync” to add your account manually.
Android to iPhone
You can transfer your content from Android to iPhone using an app like "MoveOS".
How to move your data from Android to iPhone or iPad with Move to iOS
- Follow the iPhone prompts to set up your iPhone until you reach the screen titled "Apps & Data".
Tap "Move Data from Android" option.
- On your Android phone or tablet, open the Google Play Store and search for Move to iOS.
- Open the Move to iOS app listing.
- Tap Install
- Tap to accept the permissions request.
Tap Open after it's installed.
- Tap Continue on both devices.
Tap Agree and then Next on the Android phone or tablet.
- On your Android device, enter the 12-digit code displayed on the iPhone or iPad.
After entering the code, the Android device will connect with your iPhone or iPad over a peer-to-peer Wi-Fi connection and determine what data will be transferred.
It will ask whether you want to transfer your Google Account info (so that you can quickly log in on your new Apple device), Chrome bookmarks, text messages, contacts, and the photos and videos in your camera roll. Select everything you want to move over.
Your Android phone or tablet will transfer the selected data over to your iPhone or iPad and place the appropriate content into the correct apps. The two devices will disconnect and Android will prompt you to take your old device to the Apple Store, where they'll recycle it for free.
Once the transfer process is complete, tap on Continue Setting Up iPhone or Continue Setting Up iPad on your device and carry on setting up a new Apple ID or logging into your existing one.
Once the setup process is completed, you'll be prompted to log in to the accounts you transferred from your old Android device
*Information retrieved from: https://www.imore.com/how-switch-from-android-iphone-ipad