Back up your WhatsApp chats on your old phone
Open WhatsApp
Go to Settings
Tap Chats
Tap Chat backup
Tap Back Up
Make sure the backup completes
Install WhatsApp on your new phone
Sign in with the same phone number
Verify your number with the code sent to you
When prompted, tap Restore
Wait for the chats and media to finish restoring
Open WhatsApp and check that your chats are transferred
If using Android to Android, use Google Drive backup
If using iPhone to iPhone, use iCloud backup
If moving between Android and iPhone, use WhatsApp’s transfer chat feature if available
Keep both phones connected to Wi-Fi and power during the transfer