Here are some ways to back up your Android phone: 

Android You can back up your Android phone to Google Drive using the built-in backup feature: 

Open your phone’s Settings app  Tap Google  Tap Backup  If this is your first time, follow the on-screen instructions to turn on backup  Tap Back up now  Select the data you want to back up, such as photos, videos, device data, or both 

Backup an Apple iPhone

Here are some ways to back up your iPhone:
iCloud: Back up your iPhone to iCloud automatically or manually:
Connect to Wi-Fi
Go to Settings > [your name] > iCloud > iCloud Backup
Turn on Backup This iPhone
To back up manually, tap Back Up Now
To enable automatic backups, make sure the switch is toggled on

iCloud backups include most of your device’s information and settings, but not everything. For example, iCloud backups don’t include data already synced to iCloud, photos if you use iCloud Photos, or messages if you sync messages with iCloud.

Under iCloud settings view all to make sure all content you want backed up is selected. I see some people forget to backup message and they lose their texts if not on.

Computer: Use Finder or iTunes to back up your iPhone to your computer:
Open Finder and look for your iPhone in the left-hand menu
Select the General tab and look for the Backups category
Select Back up all of the data on your iPhone to this Mac
Encrypt your backup for increased security
Click Back Up Now to start the backup
To restore your backup, go to the same page and click on Restore Backup