If you can't connect to WhatsApp, this is usually caused by a problem with your Internet connection or your phone's settings. It might not be necessary to delete and reinstall WhatsApp.

Troubleshooting

Most connection issues can be resolved by doing the following:

• Restart your phone, by turning it off and back on.
• Update WhatsApp to the latest version available from the Apple App Store.
• Open iPhone Settings and turn Airplane Mode on and off.
• Open iPhone Settings > tap Cellular and turn Cellular Data on.
• Open iPhone Settings > tap Wi-Fi and turn Wi-Fi off and on.
• Try connecting to different Wi-Fi hotspots.
• Make sure Wi-Fi stays on during sleep mode.
• Reboot your Wi-Fi router.
• Contact your mobile provider and make sure your APN settings are configured correctly.
• Open iPhone Settings > tap General > Reset> Reset Network Settings > Reset Network Settings. (This will delete all your saved Wi-Fi passwords).
• Upgrade or restore your iPhone's operating system to the latest version for your phone.
• If you're using an unlocked iPhone or a pre-paid SIM card, you might need to adjust your phone's APN settings for your SIM card. Contact your mobile carrier for details and instructions.
• If you're having trouble connecting to WhatsApp while on a Wi-Fi network that you don't normally connect to, contact the network administrator.
• Make sure your connection isn't on a managed Wi-Fi network, such as at your office or university campus. Your network might be configured to block or limit connections.
• WhatsApp isn't designed to be used with proxy or VPN services, so we can't provide support for those configurations.
• Turn off roaming.

For issues with receiving notifications for WhatsApp messages, read this article.