By default, WhatsApp will automatically download images over your cellular connection to provide you with quick access to your latest photos.
To configure automatic photo, video, or audio downloading, simply go to WhatsApp > Menu Button > Settings > Data Usage.
Here you can choose when WhatsApp will automatically download media.
Selected media will automatically download when you are connected to cellular data.
Selected media will automatically download when you are connected to Wi-Fi.
Selected media will automatically download when you are roaming.
Note: Enabling auto-download when roaming may result in significantly increased charges from your mobile provider as roaming data is often expensive.
Automatically downloaded media will show up in your gallery. If you want to stop all WhatsApp media from appearing in your gallery, we recommend that you create a .nomedia file or folder inside of your WhatsApp images, audio, and video folder. You can do this using a file explorer. If you change your mind later, you can simply delete the .nomedia file and WhatsApp media will show up in your gallery again.
WhatsApp Support Team