After iOS 9 no storage space freed up on iPhone 6 plus

I would guess that the download was compressed so that the working size of iOS9 is pretty much the same that of iOS8.

I think you have got the wrong end of the stick. What Apple meant was that the update files for iOS 9 are a lot smaller than 8. i.e. the files required to update to iOS 9 is smaller. It will not free up any space on your phone.

Apple never said that you'd end up with loads more space after iOS9. All they said was that the installation process would be streamlined so that much less free space would be needed on the device to actually get it installed. This was borne out on my 16 mb iPad, on which I was able to install the update with only about 500mb free space. Previously I would have had to delete loads of apps and data to get updates installed.

I had the same problem. On early Apple Support contact, this morning, I was informed that the IOS 9 really use 1.3 GB after its installation.

On my iPhone 6, 16 GB, I had about 3.5 GB of apps and data, so, I expected at least 6.5GB free ...

ashleydelavane wrote:

There is also meant to be more storage saved in the future as app designers update their apps for iOS 9 which is only meant to download the version of an app that is relevant to model of Apple device- instead of an app that incorporates all device versions.

This feature is called App Thinning and you may never notice the difference other than on very large apps. If an app is only 20MB, app thinning may only free up a couple of megabytes. Even on a large app, you probably won't see anything show you how much space you saved through app thinning.

I think the problem is solved. I took the Apple Support advice and work for me:

1) Make a full backup (*)

2) Go to Setup / General / Reset / Erase All Content and Settings

3) Reinitialize iPhone with last backup made (*)

(*) This I made with iCloud (Wi-Fi mode)

after those steps, some space got freed? 🙂

Yeah ! I had 3.2 GB free before. Now I have 8.4 GB free !

Sure, not everything was easy. After apps restored from last iCloud backup, my music, that are not from Apple Music catalog (like some CD copies I made from Beatles), vanished ... That, I needed to restore myself.

On my 16GB iPhone 6, I updated from 8.4.1 to 9.0 over the air. Storage capacity was 11.8 GB prior to upgrade. After upgrade, storage capacity is still 11.8 GB.

On a spare, data-less 32GB iPhone 4S, I updated from 8.4.1 to 9.0 over the air. Storage capacity was 27.2 prior to upgrade. After upgrade, storage capacity is still 27.2 GB. I then downloaded the iOS 9.0 ipsw file for my iPhone 4S. I connected the 4S to iTunes, did a Shift-Left click on the Restore iPhone button to force it to restore from the ipsw file I downloaded, effectively erasing everything on the device and installing the new iOS 9 from scratch. Storage capacity on the device still says 27.2 GB, iTunes also says storage capacity is 27.2 GB.

If there is any data storage increase, I believe the latter process would have found it.

There apparently is no storage capacity increase using iOS 9.

I went one step further with the data-less 32GB iPhone 4S. I powered the phone off, held the Home button and plugged in the USB cable so that iTunes would recognize a phone was in recovery mode. Once again, using the Shift-Left Click on the Restore iPhone button, I restored the iPhone via 9.0 ipsw file. Storage capacity is still at 27.2 GB.