Check whether your chats are still on the phone and just archived
Open WhatsApp and go to Archived Chats
Unarchive any chat you want to restore
Restore from a recent WhatsApp backup
Uninstall WhatsApp
Reinstall WhatsApp from the App Store or Google Play Store
Verify the same phone number
Tap Restore when prompted
Wait for the chats to finish restoring
Restore from Google Drive backup on Android
Make sure you are signed into the same Google account used for backup
Confirm a backup exists in WhatsApp settings
Reinstall WhatsApp and restore when prompted
Restore from iCloud backup on iPhone
Make sure you are signed into the same Apple ID used for backup
Confirm iCloud Drive is enabled
Reinstall WhatsApp and restore when prompted
Restore from local backup on Android
Use a file manager to check the WhatsApp Databases folder
Find the backup file you want to restore
Rename the backup file if needed
Reinstall WhatsApp and restore from local backup
Check if the chat was deleted from the device but still exists in a backup
Restore the backup that contains the missing chat
Avoid making a new backup before restoring the old one
Ask the other person to resend the chat or media if no backup exists
Export chats from another device if the account is linked and the chat is available there
Keep automatic backups turned on to prevent future loss
Back up chats regularly in WhatsApp settings