This method involves using a newer iOS device (or an emulator) to register that you own the app, then downloading it on your older device. Step 1: Use a Newer Device
Apple’s policy requires that the app must have been purchased (or downloaded for free) at least once using your Apple ID on any device. If you have a brand new Apple ID that has never downloaded WhatsApp, the "last compatible version" trick will not work. whatsapp old version for ios 9.3.6 download
The only legitimate method is the "App Store Purchase History" trick. If you had previously installed WhatsApp on that Apple ID in the past, you can go to the "Purchased" tab in the App Store, find WhatsApp, and hit download. The system will prompt you with: "Download an older version of this app? The current version requires iOS 10 or later." Once you accept, you get the last compatible build (usually version 2.19 or similar). This method involves using a newer iOS device
Account Bans: WhatsApp actively scans for modified or unauthorized clients. If you connect to their servers using an altered app, your phone number could be permanently banned from the platform. Important Limitations After Installation The only legitimate method is the "App Store
Once the download completes, the app from this newer device (don't worry, the "purchase" is now linked to your ID). Step 2: Download on iOS 9.3.6 Open the App Store on your iPhone 4S/5 running iOS 9.3.6. Go to the "Purchased" tab. Find WhatsApp in the list and tap the cloud download icon.