option to change media storage path to ext. SD

FYI, I have sent the following email to WhatsApp. Feel free to copy and send them, too:
"
Dear WhatsApp team, please add the option in settings to specify the media storage path, so videos/ images/ voice messages can get saved onto external SD, instead of clogging up the internal SD. WhatsApp has been limping behind all other apps I use in that regard, and it's so easy to implement this absolutely basic feature. So please finally catch up with your competition so I can add 3 more stars *. Thank you all.
"
android@support.whatsapp.com

and in addition you can also leave a review with your comment at play.google.com/store/apps/details?id=com.whatsapp

— modified on May 3, 2017, 9:22:36 PM

Needless to say I am not the first to stumble across this missing feature, see faq.whatsapp.com/en/android/21068307

So until they hire better coders, DIY (manual based on source from quora.com/How-can-I-make-my-SD-card-as-a-default-storage-for-the-WhatsApp-media ):

NOTE: it is NOT enough to just apply below work-around to the media folder only (/WhatsApp/media), because then WA will NOT be able to save new incoming media!!

Change WhatsApp storage path to external SD

1. Root your device.

2. Download and install "Folder Mount [ROOT]" play.google.com/store/apps/details?id=com.devasque.fmount (freely available for max. 3 pairings)

3. Start FolderMount

4. Approve FolderMount's superuser request.

5. Click on the "+" icon at the top-right of the "List of pairs" screen (the homescreen).

6. Give it a the name "WhatsApp"

7. Tap on the textbox underneath "Source", navigage to the source folder (/storage/emulated/0/WhatsApp) and tap the tick icon at the top-right to confirm your selection.

8. Choose whether to automatically create the destination folder. If you choose "Yes", FolderMount will create a folder with the same name in your external SD-card (/storage/sdcard1/WhatsApp, most likely). If you choose "No", you'll have to select the destination folder yourself. This works the same way as selecting the source folder.

9. Choose whether to exclude destination files from Android media scan results or not. It's recommended that you turn this feature on, as otherwise those media files will show up twice in apps like the built-in Gallery.

10. Choose whether to move everything from the source folder to the destination folder, or not. If the destination folder is empty (which will be the case if it was automatically created by FolderMount), you can safely choose "Yes". (only if it pre-exists and isn't empty, it might be best to choose "No" and copy everything yourself with a file explorer app)

11. You should be back in the "List of pairs" screen.
    If you chose to move all files from the source folder to the destination folder in the last step, wait until that's finished (you can track the progress with the notification that appears) before doing this.

12. The last step is to flick the switch next to "WhatsApp" to the on position. This ensures that the source and destination folders are linked together, and that the destination folder appears as the source folder.

Et voilà !

— modified on Aug 25, 2018, 11:48:12 PM