How to save my iPhone photos permanently in iCloud Drive so that I can delete them from my iPhone?

[iMore Question]

I'm able to do one photo but can't seem to do multiple photos at one time. When I select multiple photos then hit ^ arrow it doesn't show iCloud Drive like it does with just one photo is selected.

 

[robertk328]

You can't. If you delete from your phone, it will delete from iCloud Drive.

You can use a service like Dropbox to store them/back them up. You can even do it alongside iCloud Photo Library if you want.