Everything you need to know about the new Apple File System


APFS arrives in 2017.
APFS arrives in 2017.
Photo: Ste Smith/Cult of Mac

(Editor’s Note: This article was originally published in June 30, 2016, but has been updated with new info since the release of iOS 10.3)

It’s hard to believe that Apple’s speedy Macs are still using a file system that was developed more than 30 years ago, when floppy disks and spinning hard drives were considered cutting-edge technology.

But that’s going to change in 2017 with the new Apple File System — or APFS — that debuts in iOS 10.3 and macOS 10.12.4. Here’s everything you need to know about APFS and how it’s going to make your life better, no matter what Apple device(s) you use.

Why APFS makes sense, for Apple and for you

There are a whole bunch of reasons why switching to the new Apple File System makes sense for Cupertino — and for you.

One file system for all Apple products: The big advantage is that APFS can replace all the existing file systems Apple currently uses across its platforms. APFS is suitable for macOS, iOS, tvOS and even watchOS.

Optimized for today’s Apple devices: APFS is also optimized for devices that use flash and solid-state storage — like most of the products Apple sells today. The new Apple file system was built with latency in mind, which makes it particularly beneficial to mobile devices like the iPhone, iPad and Apple Watch.

File systems like Apple’s HFS+, which stems from a platform developed 30 years ago and is still used in OS X today, are instead optimized for systems with multiple drives that handle large files. These things obviously aren’t a priority on platforms like iOS, but faster boot and app loading times are.

APFS means strong encryption: The other big advantage to APFS is that it’s designed with encryption in mind. It combines the full disk encryption features found in the latest versions of OS X with the data protection feature that encrypts every file individually on iOS.

This fits Apple’s focus on privacy and security perfectly. When APFS is made available, you’ll have three options to choose from on macOS: no encryption, single-key encryption and multi-key encryption with per-file keys for file data and a separate key for sensitive metadata.

New Apple File System is future-proof

Not only does APFS come with new features and the ability to take over everything, but it’s also built to last. Apple plans to use it for years to come, and the company has taken steps to ensure that APFS is capable of handling anything that will be thrown at it in the foreseeable future.

APFS supports 64-bit inode numbers, which improves upon the 32-bit file IDs currently supported by HFS+. What that means, in simple terms, is that APFS has the ability to carry more than 9 quintillion files on a single volume (assuming you have room for them).

This goes hand-in-hand with APFS’ extensible block allocator, which allows for “arbitrarily large storage” on a single volume. To improve performance for large volumes, APFS initializes data structures only as necessary, whereas HFS+ initializes the entire storage.

APFS also boasts 1-nanosecond timestamps (as opposed to the one-second timestamps offered by HFS+), supports space-saving sparse files (whereas HFS+ does not), and uses a novel copy-on-write metadata scheme to ensure that updates to the file system are crash-safe.

The downsides of APFS

APFS is pretty terrific, but it isn’t perfect. As it stands, it comes with a number of limitations that could be a problem for some users.

For instance, APFS can’t be used on startup disks or Apple’s Fusion Drives, and filenames are case-sensitive only. What’s more, APFS formatted drives are not recognized by OS X 10.11 Yosemite and earlier, so you won’t be able to transfer files to an older Mac using an APFS drive.

When the new Apple File System will be available

The “next-generation file system for Apple products” was introduced with the launch of iOS 10.3, macOS 10.12.4, tvOS 10.2 and watchOS 3.2 on March 27, 2017.

How to switch to APFS

Switching to the new file system is incredibly simple. All you have to do is install iOS 10.3 and all of your information is automatically switched over. You don’t need to back up your data and start again with a fresh OS install. APFS will be coming to macOS soon.

  • “You won’t need to back up your data and start again with a fresh OS install, thank God.”

    Maybe not need, but you most definitely should!

  • “You won’t need to back up your data”

    … maybe not ‘need’ but you most definitely should!

  • Steve__S

    “Apple hasn’t yet told us if these limitations will be removed before APFS makes its public debut.”
    The limitations are strongly implied to be temporary. Apple’s developer’s web site lists them and says…. “As a developer preview of this technology, there are currently several limitations:”

    • KillianBell

      Yeah, I noticed that, but it doesn’t explicitly say they won’t be there when APFS arrives.

      • Steve__S

        The point being, it’s rather silly to suggest that basic things like using APFS as a startup volume, etc. wouldn’t be supported. By definition, it has to. Similar with Time Machine (or equivalent), Fusion drives, etc.

        If you want to be critical of APFS, you should look beyond Apple’s web site and see which features they chose to omit… at least initially. There are data integrity features like checksums on user data that’s missing. They’re only doing checksums on metadata. There doesn’t seem to be any built in compression, etc. These are all things that Apple could well add later without any compatibility issues, but they are features of more cutting edge file systems and many are asking why Apple hasn’t included them.

  • Pedro Nuno

    I wish MacOs Sierra could use windows like in that picture, 3d effect :)
    It would be cool.

    • friFragt

      This article is about APFS, you’re talking about Sierra? Completely out of place, or did you miss to point completely?

      • Christopher Randall

        Did you miss grammar in school, or did you miss THE point completely?

        APFS is part of macOS Sierra, which is why Pedro commented on macOS Sierra.

  • Gaurav Pandey

    filenames are case-sensitive only – this was a nightmare (years back) but luckily they will fix it before the release.

    • Matt Eskes

      Why would having Case Sensitivity be a nightmare? As a Long Time UNIX user, Case Sensitivity only makes sense.

      • Gaurav Pandey

        I’m a sensitive guy. You may not understand.

  • Does this mean iOS may actually have a real filesystem so that apps can have shared access to it? If so, it’ll address my #1 complaint about it. OR, conversely, will it start the process of locking Mac users out of their filesystem? I’m leary either way.

  • Mike

    The immediate question that comes to my mind is: will this allow for Finder on macOS devices? And transfer of documents from Macs to iPhones and iPads DIRECTLY via iTunes (with a cable) rather than “over the air” or through the use of iCloud servers? I don’t yet have an iPad, and one of the main sticking points for me is no way to LOCALLY transfer sensitive financial, etc. documents that I don’t want “in the cloud.” I’d love to get an iPad to replace my aging Mac Book, but only if and when that (among other issues) is addressed.

  • Null Static Void

    Not looking forward to this. I don’t see any compelling reasons for this. Unlike a decade or so ago when Windows users started running into issues with FAT16 and FAT32 partitioning and the new hard drives which exceeded their OS ability to format them.
    Part of me is always a bit skeptical of such ‘improvements’. They seem to take the current generations fastest hardware as a baseline. So that any hardware even a couple years older will be penalized.
    I’d love to see Apple come out with some IOPS charts showing a performance improvement over HFS. But most likely they will ladle in a bunch of gee whiz features, written in high level language that ensures sluggish performance.
    Hopefully audio and video pros will be consulted and their workflows taken into account.

    • Matt Eskes

      I’m welcoming this change. HFS(+) is a fucking horrible nightmare.

  • I expect that to cause all sorts of problems.

    “For instance, APFS can’t be used on startup disks or Apple’s Fusion Drives, and filenames are case-sensitive only. What’s more, APFS formatted drives are not recognized by OS X 10.11 Yosemite and earlier, so you won’t be able to transfer files to an older Mac using an APFS drive.”

    This will force anyone using APFS to upgrade to Sierra (10.12) and understand that once converted to the new system, it can no longer be read on an olderMac! That could cause Mac to lose market share….

    How many offices can upgrade say 25 computers simply to be Sierra/AFPS compatible? I think Apple realizes more people use Apple handheld devices now than desktops, so the impact will be upon the creative community like Architects, Film Makers and Graphic Artists etc. who heavily use desktops than anyone else.

  • Please tell me the new filesystem will support wildcard searches?

  • Mike

    No, I wasn’t aware of that! Thanks for that link – I will look into the File Sharing option. If I determine it actually works without going through iCloud (and it appears it does) then it will be a winner! Thanks again!

  • perryrants

    incredible simple? like upgrading my ipad 9.7 into a brick simple?