Here are some of the fixes you can try if whatsapp is not working on your phone.

Make sure your internet connection is working properly. Try opening other apps which rely on the internet and see if they are working fine or not. See if the browser is working and try opening some web pages on your phone.

If everything else that depends on internet seems to work fine then try these steps to fix the issue.

Turn WiFi off and then turn in back on. For android users go to Wireless and Networks and then go to WiFi. Try connecting to other WiFi networks to test if the problem is with some specific WiFi service. If still things doesn’t work then try restarting your router.

Restart/Reboot your phone. Power off your phone and then turn in back on.

If you are using mobile data instead of WiFi then make sure mobile data is turned on and you have sufficient signals. Also make sure that you have not restricted background data usage of WhatsApp in the data usage menu. Re-check your APN configurations and make sure they are correct and confirm from your mobile provider that you are able to send and receive no-web traffic.

Turning Airplane mode on and off sometime fixes connection related issues. Go ahead and give it a try.

After making sure that you have a working internet connection, the next move is upgrade Whatsapp to latest version. For android users go to Google Play for updates and for iPhone users use the App Store to update Whatsapp to the latest version.

If all the above step doesn’t make any difference they try uninstalling and the reinstalling Whatsapp. This will erase your chat history. Make a manual backup before deleting the app by going to WhatsApp > Menu button > Settings > Chat Preferences > Backup conversations.

You can share in comments if some other method worked for you.