By default, WhatsApp for iPhone automatically saves the photos and videos you receive to your iPhone’s Camera Roll.
You can stop this if you’re not a fan of it, and here’s how:
Hit Settings at the bottom.
Tap Chats which you can find between Account and Notifications.
Beneath Chat Wallpaper, you can view Save to Camera Roll.
Hit the toggle beside it to turn it off.
From now on, WhatsApp will not automatically save the images and videos you receive to your iPhone’s Camera Roll.
And, you need to save the one you prefer manually. Let’s see how.
Tap the photo you prefer to save. Hit the Share icon at the bottom. Tap Save option in the pop-up.
Note: wish to turn on the feature? follow the steps at the top for that.