Open WhatsApp on the old phone
Go to Settings
Tap Chats
Tap Chat backup
Back up your chats to Google Drive on Android or iCloud on iPhone
Install WhatsApp on the new phone
Verify the same phone number
Restore the backup when prompted
Wait for the chats and media to finish restoring
Keep both phones connected to Wi-Fi during the process
Make sure you use the same Google account or Apple ID on the new phone
For Android to Android, use WhatsApp transfer or backup restore
For iPhone to iPhone, use iCloud backup restore
For Android to iPhone or iPhone to Android, use WhatsApp’s Move to iOS or Switch to Android transfer method
Keep WhatsApp updated on both phones
Ensure enough storage is available on the new phone