You can recover deleted messages on iPhone and Android devices. Unfortunately, since the WhatsApp messaging service does not save your chat history, messages deleted from your device are only recoverable if you have set up a backup. It is relatively simple to set up backup of WhatsApp messages on your phone so that you can easily restore them after deletion.
Steps
Method 1 of 4: Set up WhatsApp message backup on iOS

Step 1. Tap the WhatsApp app icon to open it
This icon looks like a white phone in a chat bubble on a green background.

Step 2. Select Settings
This option is in the lower right corner of the screen.

Step 3. Choose Discussions

Step 4. Tap Chat Backup

Step 5. Select Auto Backup
Choose between daily, weekly or monthly backup.
- If you haven't set up your iCloud account yet, you'll be prompted to do so before continuing with the backup. Open the app Settings, tap your name, select iCloud, make sure the iCloud Drive option is turned on and also check that the WhatsApp option is turned on.
Method 2 of 4: Recover old WhatsApp messages on iOS

Step 1. Long press the WhatsApp app icon
It will start to shiver along with all the other app icons on the screen.

Step 2. Tap the X at the top left of the icon
This will bring up a dialogue window asking you to confirm the deletion of WhatsApp.

Step 3. Choose Remove
The app will be deleted from your iPhone.

Step 4. Reinstall WhatsApp from the App Store
- Tap the App Store icon to open it. This is the white A-shaped icon on a blue background.
- Tap the icon
then enter "WhatsApp" in the search field.
- Select WhatsApp from the search results.
- Choose Get to download WhatsApp again. This option is to the right of the application name.

Step 5. Tap Open to open WhatsApp
The Open option appears instead of Get when the download is complete.

Step 6. Select Accept and Continue
Then press OK.

Step 7. Choose Allow Where Not to allow.
This allows the application to send you notifications or not.

Step 8. Enter your phone number
Then tap on Done. Make sure the phone number is the same one you used when installing WhatsApp earlier.

Step 9. Tap Restore Chat History
Then tap Next to retrieve all the chats that you have backed up to your iCloud account. This includes messages that have been deleted from WhatsApp, as long as they were still there during the last backup.

Step 10. Enter a name then tap Next
You will be redirected to the discussions page.

Step 11. Tap a name from the list
This will restore all chats associated with that contact.
Method 3 of 4: Set up WhatsApp message backup on Android

Step 1. Tap the WhatsApp app icon
This is the white phone icon inside a chat bubble on a green background.

Step 2. Select More
This is the vertically aligned 3 dots icon in the upper right corner of your screen.

Step 3. Choose Settings
This option is located at the bottom right of your screen.

Step 4. Tap Discussions

Step 5. Select Backup Discussions

Step 6. Choose Backup to Google Drive
You can choose to save your messages every day, every week or every month.
If you haven't set up your Google account yet, you'll be prompted to do so before continuing with the backup

Step 7. Tap Back Up Now
Choose the network you want to use to back up your data.
If possible, use a WiFi network to avoid the data charges associated with your cellular network
Method 4 of 4: Recover old WhatsApp messages on Android

Step 1. Tap the Play Store icon


Step 2. Go to the menu
Next, tap on My games & apps.

Step 3. Scroll down to the Installed Apps section
Tap Uninstall next to WhatsApp.

Step 4. Reinstall WhatsApp from the Play Store
- Tap the Play Store icon again
- Select the search icon
then enter "WhatsApp" in the search field.
- Choose WhatsApp from the search results and then tap Install.
- Tap the WhatsApp app icon to open it. Accept the terms of use and confirm your phone number. Make sure you are using the same phone number that was associated with the previous installation of WhatsApp.

Step 5. Select Restore
This option will restore all chats that were backed up to your Google Account, including messages that you deleted from WhatsApp (only if they were included in the last backup).

Step 6. Tap Next

Step 7. Enter the name you want to use
Then tap Next to display the chats page.

Step 8. Tap a name from the list
This will display any restored chats that you have had with that contact.