Hi friend, what kind of phone do you use? If you're an iPhone user, just follow the methods below to recover WhatsApp chat history.
If you have previously backed up your iPhone using iTunes or iCloud and are quite sure the lost data is included in the backups, you may be able to retrieve deleted WhatsApp chat history by restoring your iPhone from backup.
Method 1. Retrieve WhatsApp Chat History from iCloud Backup
To recover your chat history from an iCloud backup, first verify that an iCloud backup exists in WhatsApp Settings > Chats > Chat Backup. If you can see when the last backup was performed, delete and reinstall the app from the App Store. After verifying your phone number, follow the on-screen prompts to restore your chat history. The same iCloud backup requirements apply for iCloud restore. In addition, the phone number used for backing up and restoring must be the same. You cannot restore the chat history from another WhatsApp account. If you share an iCloud account, this will allow you to keep your backups separate.
Method 2. Retrieve WhatsApp Chat History from iTunes Backup
1. Open iTunes. First go to Edit > Settings > Devices to disable automatic syncing.
2. Connect your iPhone to computer. Wait for a while, right-click your iPhone in the devices list and click “Restore from Backup”.
3. Stay in the backup file contains WhatsApp messages, click “Restore”.
If you have no previous backup on iTunes or iCloud, you can take advantage of the third-party iPhone data recovery software to retrieve WhatsApp chat history from iPhone directly. Leawo iOS Data Recovery is one of the most powerful iPhone data recovery tools to restore WhatsApp messages and WhatsApp attachments on iPhone. It enables you to retrieve WhatsApp chat history directly from iPhone, iPad, and iPod touch, even if you have no any iTunes/iCloud backup.
http://www.leawo.org/tutorial/how-to-recover-whatsapp-chat-history-from-iphone.html