To turn off iCloud sync when using on two iPhones, you can follow the steps below to do it easily and effectively:

Step 1: First, sign in to your iCloud account on both iPhones in Settings . Make sure both devices have an internet connection for the sync to go smoothly.

Step 2: Next, after successfully logging in, continue to iCloud in the Apple ID section as shown below.

Step 3: Finally, under iCloud, select Show All . Next, select the app that you want to disable iCloud syncing on both iPhones. Finally, toggle the "Sync This iPhone" switch to gray to finish.

Now you can enjoy a seamless and optimized experience across the Apple ecosystem with this guide. If you want to turn iCloud sync back on on both iPhones, just follow the same steps and slide the switch to the right at the end.

The above article has compiled complete information about iCloud synchronization on two iPhones, helping you have a comprehensive view of this feature. At the same time, apply the method to turn off iCloud synchronization when using together to enhance security and minimize potential risks.