By default, WhatsApp will automatically download:
Photos when you’re in mobile data connection.
All media when you’re in Wi-Fi connection.
Nothing when you’re in roaming.
If you want to stop media auto-download of WhatsApp, then follow the below steps:
Hit Overflow Menu (three vertical dots) > Settings > Data and Storage usage.
Under the “Media auto-download” section, you can see three options.
If you want to stop WhatsApp saving photos when you’re using mobile data, then hit “When using mobile data” option. Now, uncheck “Photos” and then hit “Ok.”
If you want to stop the auto-download of all (Photos, Audio, Videos, and Documents) when you’re using Wi-Fi, then hit “When connected on Wi-Fi” option. Now, uncheck all options and then hit “Ok.”
By default, WhatsApp doesn’t download anything on roaming. So, you can leave the “When roaming” option intact. In case, if you’ve already selected any, then just hit “When roaming” option, uncheck the ones that are selected and tap “Ok.”
That’s it. All done.
From now on, whenever you’re receiving media files, you need to download manually (Hit the “Download” icon in the media file to do this).
Also, keep in mind the following two important things:
Voice messages will always automatically be downloaded by WhatsApp, and there isn’t an option to stop that.
You can’t stop media auto-download on WhatsApp Web.
Note: WhatsApp, by default, shows downloaded images and videos in the phone gallery. Want to hide photos and videos from the gallery? Check out this guide.