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As the title suggests i am going from iPhone 6 to iPhone 7, with a lower memory. The Iphone6 was pretty much used to the max in storage. Never use iCloud, never full under stood it, or trusted it, plus i would have to pay for more storage as you only get 5gb as standard.
Issue i have got is I've done a back up of iPhone 6....trying to restore onto my new iphone so messages/imessages are sent across etc. But it clearly doesn't like this (doing it through MacBook etc)
All really want sending across from iPhone 6 to iPhone 7 is the contacts and message threads....
Things in WhatsApp are fine, should be when i reload onto new phone
Important pictures i will just email and save to new phone
Apps, i can re-download no problem.
One thing i thought of was deleting all the pictures/videos/4gb music and spotify app and that would reduce the 'storage used' by a considerable amount, back up 6, restore on to 7 and that may work?
Typically if your usage needs are outweighing your current iPhone storage capacity I wouldn't recommend to go lower with your new iPhone.
You can't expand the iPhones inbuilt storage capacity so a person is stuck with what they've chosen.
There are Plug in gadgets for extra storage but that means needing to carry it around.
I use icloud with no issues but my storage needs are not large so 5gb is ample.
I used to buy 16gb iPhones which at first was enough.
I now use the s7 edge with a Sd card.
I also use DropBox to store information (there are other options) and gmail for contacts.
You can select in Settings > iCloud what you want to back up and then in your new phone when setting it up elect to use your iCloud back up.
I just got tired of micro managing my iPhone 6 Plus 16gb model.
Similar to you the cost to move up tiers of onboard storage can be costly.
Apple in my opinion won't introduce Sd Card slots because they want iOS to be sandboxed with little security threats.
The 'other' yellow bar will creep up so keep an eye on that. Link > Other. Usually a Restore help with that.