iCloud backup size after iPhone migration I use iCloud backups for long time.  When I started out I could easily backup a 128GB iPad Air and a 32 GB iPhone5s to the 5GB of default iCloud storage. I recently switched phone to a 64GB iPhoneSE and now the backup size increased a lot with no apparent reason.  Here's a screenshot of how the storage breaks down.  It's in German, but I think it's clear. There is about 1GB of app data including photos and the total backup size is 4GB.  Before the switch to the new phone it was 2GB total with 1GB app data.  What are these 2GB and how can I get rid of them?



Update: Here is another observation. If I delete my iCloud backup and do a fresh backup it comes at about 2GB total size (which is what I expect).  After two days including taking lots of pictures, transfering them to the Mac, syncing them back etc., however, I was back at 4GB.
After talking to Apple Support and trying various things, I conclude that this is a bug in iCloud.

I've made the following observations:


Backups to iTunes always have the size they should have (about 2.8GB in my case)
Backups to iCloud when first created are of the correct size and then constantly grow (after I month I saw about 10GB).
Apple Support has no solution to offer except to periodically delete the iCloud backup and recreate it from scratch.


For reference, this only started after I migrated my iPhone 5S to an iPhone SE via an iTunes backup.  Before this migration iCloud backups worked as expected.

Edit in 2018: indeed the bug was fixed later and backup size went back to normal a few weeks after this answer.