Do I have to download all my iCloud library pictures to my phone when I turn on iCloud?
I just want to upload my pics to iCloud so I can free up space on my phone.
But it does the opposite because imy entire iCloud photo library downloads onto my phone .
iPhone 6, iOS 8.4.1, null
That is how iCloud Photo Library works. If you turn it on, all of your pictures will be on iCloud and they will also be on every device where you have turned on iCloud Photo Library. The most you can do to reduce the space required on your phone is to turn on Settings > iCloud > Photos > Optimize iPhone Storage. All of the photos will still be on your phone but if the phone is low on space the full resolution photos will be replaced with smaller optimized versions.
If you want more options in the future you may want to provide feedback to Apple at http://www.apple.com/feedback/icloud.html
In the meantime, if you require cloud-only storage, there are some 3rd parties where that is an option, including Dropbox and Flickr.
iCloud Photo Library
