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{{distinguish|text=Apple File Service (AFS), the service implementing the [[Apple Filing Protocol]] (AFP)}}
{{distinguish|text=[[Andrew File System]] (AFS), the distributed file system}}
{{Use mdy dates|date=May 2018}}
{{Infobox filesystem
| name
| full_name
| developer
| introduction_os
| introduction_date
|'''iOS''': {{date and age|27 March 2017 | p=y}}
| partition_id = <code>7C3457EF-0000-11AA-AA11-00306543ECAC</code> ([[GUID Partition Table|GPT]])▼
|'''macOS''': {{date and age|25 September 2017 | p=y}}
| directory_struct = [[B-tree]]<ref name="hansenToolan2017">{{Cite journal|last1=Hansen|first1=K.H.|last2=Toolan|first2=F.|date=September 21, 2017|title=Decoding the APFS file system|journal=Digital Investigation|volume=22|pages=107–132|doi=10.1016/j.diin.2017.07.003|issn=1742-2876|df=mdy-all}}</ref>▼
}}
| max_files_no = 9,223,372,036,854,775,808<ref name="appleVolumeComparision"/>▼
| preceded_by = [[HFS Plus]]
| max_file_size = 8 [[Exbibyte|EiB]] (9,223,372,036,854,775,808 bytes)<ref name="appleVolumeComparision">{{Cite web|url=https://developer.apple.com/library/content/documentation/FileManagement/Conceptual/APFS_Guide/VolumeFormatComparison/VolumeFormatComparison.html|title=Volume Format Comparison|website=Apple Developer|language=en|access-date=May 25, 2018|df=mdy-all}}</ref>▼
| succeeded_by =
| date_range = January 1, 1970 – July 21, 2554<ref name="hansenToolan2017"/>▼
| date_resolution = 1 [[Nanosecond|ns]]<ref name="appleVolumeComparision"/>▼
▲| directory_struct
| max_filename_size = ▼
| filename_character_set = [[Unicode|Unicode 9.0]] encoded in [[UTF-8]]<ref name="appleApfsFaq2018"/>▼
▲| max_file_size
| dates_recorded = access, attributes modified, contents modified, created▼
▲| date_range =
▲| filename_character_set
| file_system_permissions = Unix permissions, [[NFSv4]] [[Access control list|ACL]]s
| compression
| encryption
| copy_on_write
| OS
| website
}}
'''Apple File System''' ('''APFS''') is a [[Proprietary software|proprietary]] [[file system]] developed and deployed by [[Apple Inc.]] for [[macOS]] [[macOS Sierra| Sierra (10.12.4)]]<ref name="TechRepublic 2017.04.13">{{cite news |last1=Vigo |first1=Jesus |title=How to set up and use Apple's APFS file system on macOS Sierra |url=https://www.techrepublic.com/article/how-to-set-up-and-use-apples-apfs-file-system-on-macos-sierra/ |publisher=TechRepublic |date=13 Apr 2017}}</ref> and later, [[iOS]] [[iOS 10 |10.3]]
== History ==
Apple File System was announced at [[Apple Inc.|Apple]]'s [[Apple Worldwide Developers Conference|developers’ conference]] (WWDC) in June 2016 as a replacement for [[HFS Plus|HFS+]], which had been in use since 1998.<ref name="9to5Mac APFS announced">{{cite web |first=Seth |last=Weintraub |title=Apple File System (APFS) announced for 2017, scales 'from Apple Watch to Mac Pro' and focuses on encryption |url=https://9to5mac.com/2016/06/13/apple-file-system-apfs/ |website=9to5Mac |date=June 13, 2016 |access-date=March 27, 2017 |url-status=live |archive-url=https://web.archive.org/web/20170328195315/https://9to5mac.com/2016/06/13/apple-file-system-apfs/ |archive-date=March 28, 2017 |df=mdy-all }}</ref><ref name="Ars APFS spotted">{{cite web |first=Lee |last=Hutchinson |title=New file system spotted in macOS Sierra [Updated] |url=https://arstechnica.com/apple/2016/06/new-apfs-file-system-spotted-in-new-version-of-macos/ |website=[[Ars Technica]] |publisher=[[Condé Nast]] |date=June 13, 2016 |access-date=March 27, 2017 |url-status=live |archive-url=https://web.archive.org/web/20170328195529/https://arstechnica.com/apple/2016/06/new-apfs-file-system-spotted-in-new-version-of-macos/ |archive-date=March 28, 2017 |df=mdy-all }}</ref> APFS was released for [[64-bit computing|64-bit]] [[iOS]] devices on March 27, 2017, with the release of iOS 10.3, and for macOS devices on September 25, 2017, with the release of [[MacOS High Sierra|macOS 10.13]].<ref name="macrumors-ios10_3">{{cite web |first=Juli |last=Clover |title=Apple Releases iOS 10.3 With Find My AirPods, APFS, App Store Review Tweaks and More |url=https://www.macrumors.com/2017/03/27/apple-releases-ios-10-3/ |website=[[MacRumors]] |date=March 27, 2017 |access-date=March 27, 2017 |url-status=live |archive-url=https://web.archive.org/web/20170327194444/https://www.macrumors.com/2017/03/27/apple-releases-ios-10-3/ |archive-date=March 27, 2017 |df=mdy-all }}</ref><ref name="The Verge update today">{{cite web |first=Tom |last=Warren |title=Apple is upgrading millions of iOS devices to a new modern file system today |url=https://www.theverge.com/2017/3/27/15076244/apple-file-system-apfs-ios-10-3-features |website=[[The Verge]] |publisher=[[Vox Media]] |date=March 27, 2017 |access-date=March 27, 2017 |url-status=live |archive-url=https://web.archive.org/web/20170327184802/http://www.theverge.com/2017/3/27/15076244/apple-file-system-apfs-ios-10-3-features |archive-date=March 27, 2017 |df=mdy-all }}</ref>
Apple released a partial specification for APFS in September 2018 which supported read-only access to Apple File Systems on unencrypted, non-Fusion storage devices. The specification for software encryption was documented later.<ref>{{cite web |title=Apple File System Reference |url=https://developer.apple.com/support/downloads/Apple-File-System-Reference.pdf |publisher=Apple Developer}}</ref>
==Design==
The file system can be used on devices with relatively small or large amounts of storage. It uses 64-bit [[inode]] numbers,<ref name="appleVolumeComparision"/> and allows for more secure storage
=== Partition scheme ===
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=== Clones ===
Clones allow the operating system to make efficient file copies on the same volume without occupying additional storage space. Changes to a cloned file are saved as [[Delta encoding|delta extents]], reducing storage space required for document revisions and copies.<ref name="digging-into-apfs"/> There is, however, no interface to mark two copies of the same file as clones of the other, or for other types of [[data deduplication]].
The feature is automatically available when a user copies any files using the [[Finder (software)|Finder]] application, which is [[macOS]]'s default [[file manager]], but not when using the <code>[[cp (Unix)|cp]]</code> command.<ref>{{cite web|title=A ZFS developer's analysis of the good and bad in Apple's new APFS file system|website=Ars Technica|date=2016-06-26|url=https://arstechnica.com/gadgets/2016/06/a-zfs-developers-analysis-of-the-good-and-bad-in-apples-new-apfs-file-system/|ref={{sfnref|Ars Technica|2016}}|access-date=2025-02-17|quote="Side note: Finder copy creates space-efficient clones, but cp from the command line does not."}}</ref> To do that on the [[command-line]], the <code>cp</code> utility on macOS has a <code>-c</code> parameter that allows it to use the <code>clonefile</code> [[system call]].<ref>{{cite web|title=[dedup] Use APFS clone (CoW) on macOS · Issue #219 · pkolaczk/fclones|website=GitHub|date=2023-08-10|url=https://github.com/pkolaczk/fclones/issues/219|access-date=2025-02-17}}</ref>
=== Snapshots ===
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===Increased maximum number of files===
APFS supports 64-bit [[inode number]]s, supporting over 9 quintillion files (2<sup>63</sup>) on a single volume.<ref name="appleVolumeComparision"/><ref name="appleFileSystemGuide">{{cite web|url=https://developer.apple.com
=== Data integrity ===
Apple File System uses [[checksum]]s to ensure [[data integrity]] for [[file system#metadata|metadata]] but not for the actual user data, relying instead on [[error-correcting code]] (ECC) mechanisms in the [[computer data storage|storage]] [[computer hardware|hardware]].<ref name="leventhalPage5">{{cite web|url=http://dtrace.org/blogs/ahl/2016/06/19/apfs-part5/|author=Adam Leventhal|date=June 19, 2016|title=APFS in Detail: Data Integrity|url-status=live|archive-url=https://web.archive.org/web/20160621060302/http://dtrace.org/blogs/ahl/2016/06/19/apfs-part5/|archive-date=June 21, 2016|df=mdy-all}}</ref>
=== Crash protection ===
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=== Limited integrity checks for user data ===
APFS does not provide checksums for user data.<ref>{{Cite web|url=https://arstechnica.com/gadgets/2016/06/a-zfs-developers-analysis-of-the-good-and-bad-in-apples-new-apfs-file-system/|title=A ZFS
=== Performance on hard disk drives ===
Enumerating files, and any [[inode]] metadata in general, is much slower on APFS when it is located on a [[hard disk drive]] (HDD). This is because instead of storing [[File system#metadata|metadata]] at a fixed ___location like [[HFS+]] does, APFS stores them alongside the actual file data.
Besides that, a key feature of APFS is "[[copy-on-write]]," which allows for rapid file duplication by creating references to the original data rather than copying it outright. This feature enables functionalities like [[snapshot (computer storage)|snapshot]]s and quick file copies. However, when files are modified after being copied, APFS creates new extents ([[data block]]s) for the changes, leading to more fragmentation over time. This issue is exacerbated with applications like [[Time Machine (macOS)|Time Machine]], which creates multiple versions of files, further increasing fragmentation and slowing [[computer performance|performance]].<ref>{{cite web|title=APFS Is Not Yet Ready for Traditional Hard Drives|website=Larry Jordan|date=2017-12-03|url=https://larryjordan.com/blog/apfs-is-not-yet-ready-for-traditional-hard-drives/|ref={{sfnref|Larry Jordan|2017}}|access-date=2025-02-17}}</ref> As a result, APFS is generally not recommended for use on HDDs, particularly for workloads involving frequent file modifications, copying, or snapshot usage.<ref>{{cite web|last=Tim|first=OWC|title=Using APFS On HDDs ... And Why You Might Not Want To|website=Rocket Yard|date=2017-11-29|url=https://eshop.macsales.com/blog/43043-using-apfs-on-hdds-and-why-you-might-not-want-to/|access-date=2025-02-17}}</ref>
=== Compatibility with Time Machine prior to macOS 11===
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== Security issues ==
* In March 2018, the APFS driver in High Sierra was found to have a bug that causes the disk encryption password to be logged in plaintext.<ref>{{cite web |title=Uh Oh! Unified Logs in High Sierra (10.13) Show Plaintext Password for APFS Encrypted External Volumes via Disk Utility.app |url=https://www.mac4n6.com/blog/2018/3/21/uh-oh-unified-logs-in-high-sierra-1013-show-plaintext-password-for-apfs-encrypted-external-volumes-via-disk-utilityapp |website=mac4n6 |date=March 21, 2018 |access-date=11 November 2019}}</ref>
* In January 2021, the APFS driver in iOS < 14.4, macOS < 11.2, watchOS < 7.3, and tvOS < 14.4 was found to have a bug that allowed a local user to read arbitrary files, regardless of their permissions.<ref>{{cite news |title=About the security content of iOS 14.4 and iPadOS 14.4 - Apple Support |url=https://support.apple.com/en-us/HT212146 |website=Apple Support |access-date=7 February 2021}}</ref><ref>{{cite web |title=About the security content of macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave - Apple Support |url=https://support.apple.com/en-us/HT212147 |website=Apple Support |access-date=7 February 2021}}</ref><ref>{{cite web |title=About the security content of watchOS 7.3 - Apple Support |url=https://support.apple.com/en-us/HT212148 |website=Apple Support |access-date=7 February 2021}}</ref><ref>{{cite web |title=About the security content of tvOS 14.4 - Apple Support |url=https://support.apple.com/en-us/HT212149 |website=Apple Support |access-date=7 February 2021}}</ref>
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=== macOS ===
An experimental version of APFS, with some limitations, is provided in [[macOS Sierra]] 10.12.4. It is available through the command line <code>diskutil</code> utility. Among these limitations, it does not perform [[Unicode normalization]] while HFS+ does,<ref>{{Cite web|url=https://mjtsai.com/blog/2017/03/24/apfss-bag-of-bytes-filenames/|title=Michael Tsai - Blog -
Since [[macOS High Sierra | macOS 10.13 High Sierra]], all devices with flash storage are automatically converted to APFS.<ref name=prepForAPFS>{{cite web | url=https://support.apple.com/en-gb/HT208018 | title=Prepare for APFS in macOS High Sierra | work=Apple.com | date=September 7, 2017 | access-date=September 19, 2017 | df=mdy-all}}</ref> As of [[macOS Mojave | macOS 10.14 Mojave]], [[Fusion Drive]]s and hard disk drives are also upgraded on installation.<ref>{{cite web | url=https://arstechnica.com/features/2018/09/macos-10-14-mojave-the-ars-technica-review/3/ | title=macOS 10.14 Mojave: The Ars Technica review | work=arstechnica.com | date=September 25, 2018 | access-date=December 20, 2018 | df=mdy-all}}</ref> The primary user interface to upgrade does not present an option to opt out of this conversion, and devices formatted with the High Sierra version of APFS will not be readable in previous versions of macOS.<ref name=prepForAPFS /> Users can disable APFS conversion by using the installer's <code>startosinstall</code> utility on the command line and passing <code>--converttoapfs NO</code>.<ref>{{cite web|last1=Trouton|first1=Rich|title=Using the macOS High Sierra OS installer's startosinstall tool to avoid APFS conversion|url=https://derflounder.wordpress.com/2017/09/26/using-the-macos-high-sierra-os-installers-startosinstall-tool-to-avoid-apfs-conversion/|website=Der Flounder|access-date=January 16, 2018|date=September 26, 2017|df=mdy-all}}</ref>
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=== Third-party utilities ===
{{Update-section|reason=Software companies have had a long time to update their software to support APFS. The article should reflect recent developments.|date=August 2025}}
Despite the ubiquity of APFS volumes in today's Macs and the format's 2016 introduction, third-party repair utilities continue to have notable limitations in supporting APFS volumes, due to Apple's delayed release of complete documentation. According to Alsoft, the maker of DiskWarrior, Apple's 2018 release of partial APFS format documentation has delayed the creation of a version of DiskWarrior that can safely rebuild APFS disks.<ref>{{cite web | url=https://www.alsoft.com/diskwarrior5apfs | title=DiskWarrior 5.2 & Apple File System (APFS) | access-date=2020-06-28}}</ref> Competing products, including MicroMat's TechTool and Prosoft's Drive Genius, are expected to increase APFS support as well.
[[Paragon Software Group]] has published a [[software development kit]] under the 4-Clause [[BSD License]] <!-- Not OSI approved, so not really open source? --> that supports read-only access of APFS drives.<ref>{{cite web |title=Paragon Software Group Releases Free Paragon APFS SDK Community Edition for Software Developers, OEMs, Forensic Experts |url=https://www.paragon-software.com/paragon-software-group-releases-free-paragon-apfs-sdk-community-edition-for-software-developers-oems-forensic-experts/ |website=Paragon Software Group}} [https://github.com/Paragon-Software-Group/paragon_apfs_sdk_ce GitHub]</ref> An independent read-only [[open source]] implementation by Joachim Metz, libfsapfs, is released under [[GNU Lesser General Public License]] v3. It has been packaged into [[Debian]], [[Fedora Linux]], [[Rocky Linux]], [[Red Hat Enterprise Linux]] and [[Ubuntu]] software repositories.<ref>{{cite web |title=libyal/libfsapfs |url=https://github.com/libyal/libfsapfs |website=GitHub |date=7 November 2019 |quote=Library and tools to access the Apple File System (APFS)}}</ref><ref>{{Cite web |title=apfs-fuse - Fedora Packages |url=https://packages.fedoraproject.org/pkgs/apfs-fuse/apfs-fuse/ |access-date=2022-10-20 |website=packages.fedoraproject.org}}</ref><ref>{{Cite web |url=https://rhel.pkgs.org/9/forensics-x86_64/apfs-fuse-20200928-1.el9.x86_64.rpm.html|title=apfs-fuse-20200928-1.el9.x86_64.rpm|website=rhel.pkgs.org}}</ref> Both are command-line tools that do not expose a normal filesystem driver interface. There is a [[Filesystem in Userspace]] (FUSE) driver for Linux called apfs-fuse with read-only access.<ref>{{cite web |last1=Ross |first1=Alistair |title=How to mount macOS APFS disk volumes in Linux |url=https://linuxnewbieguide.org/how-to-mount-macos-apfs-disk-volumes-in-linux/ |website=The Ultimate Linux Newbie Guide |date=23 February 2019}} ([https://github.com/sgan81/apfs-fuse Github])</ref> An "APFS for Linux" project is working to integrate APFS support into the Linux kernel.<ref>{{cite web |title=linux-apfs/linux-apfs-rw: APFS module for linux, with experimental write support |url=https://github.com/linux-apfs/linux-apfs-rw |website=GitHub |publisher=APFS for Linux |date=4 Feb 2022}}</ref>
A commercial product, Paragon's APFS for Windows, allows for read and write support to APFS volumes in all versions of Windows from Windows 7 through Windows 11 and Windows Server 2008 R2 through Windows Server 2022, but it is unable to format or verify APFS volumes, and it cannot read APFS volumes which are hardware-encrypted against the [[Apple T2]] security chip.<ref>{{cite web |title=APFS for Windows {{!}} Paragon Software |url=https://www.paragon-software.com/home/apfs-windows/ |website=Paragon Software Group |access-date=29 January 2024}}</ref>
== See also ==
*[[Comparison of file systems]]
==Notes==
:A.{{note label|disputed|A|none}}Disputed <ref>{{Cite web |title=libfsapfs/documentation/Apple File System (APFS).asciidoc at main · libyal/libfsapfs |url=https://github.com/libyal/libfsapfs/blob/main/documentation/Apple%20File%20System%20(APFS).asciidoc |access-date=2025-05-30 |website=GitHub |language=en}}</ref>
== References ==
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