OS X El Capitan

System requirements

All Macintosh computers that can run Mountain Lion, Mavericks, or Yosemite can run El Capitan, although not all of its features will work on older computers. For example, Apple notes that the newly available Metal API is available on "all Macs since 2012".

These computers can run El Capitan, provided they have at least 2GB of RAM:

Of these computers, the following five models were equipped with 1GB RAM as the standard option on the base model when they were shipped originally. They can only run OS X El Capitan if they have at least 2GB of RAM.

The following computers support features such as Handoff, Instant Hotspot, AirDrop between Mac computers and iOS devices, as well as the new Metal API:

The upgrade varies in size depending upon which Apple Mac computer it is being installed on, in most scenarios it will require about 6 GB of disk space.

Features

OS X El Capitan includes features to improve the security, performance, design and usability of OS X. Compared to OS X Yosemite, Apple says that opening PDFs is four times faster, app switching and viewing messages in Mail is twice as fast and launching apps is 40% faster. The maximum amount of memory that could be allocated to the graphics processor has been increased from 1024 MB to 1536 MB on Macs with an Intel HD 4000 GPU. OS X El Capitan supports Metal, Apple's graphics API introduced in iOS 8 to speed up performance in games and professional applications. Apple's typeface San Francisco replaces Helvetica Neue as the system typeface. OS X El Capitan also adopts LibreSSL in replacement of OpenSSL used in previous versions.

Window management

OS X El Capitan introduces support for snapping two windows side by side to create a split view pressing the green button on left upper corner of the window, similar to the snap-assist feature in Windows 7 (and later) and several Linux desktop environments, such as GNOME. OS X El Capitan improves Mission Control to incorporate this feature across multiple spaces. It also enables users to spot the pointer more easily by enlarging it by shaking the mouse or swiping a finger back and forth on the trackpad.

Messages and Mail

OS X El Capitan adds multi-touch gestures to applications like Mail and Messages that allow a user to delete or mark emails or conversations by swiping a finger on a multi-touch device, such as a trackpad. OS X also analyzes the contents of individual emails in Mail and uses the gathered information in other applications, such as Calendar. For example, an invitation in Mail can automatically be added as a Calendar event.

Maps

Apple Maps in El Capitan shows public transit information similar to Maps in iOS 9. This feature was limited to a handful of cities upon launch: Baltimore, Berlin, Chicago, London, Los Angeles, Mexico City, New York City, Paris, Philadelphia, San Francisco, Shanghai, Toronto and Washington D.C.

Notes

The Notes application receives an overhaul, similar to Notes in iOS 9. Both applications have more powerful text-processing capabilities, such as to-do lists (like in the Reminders application), inline webpage previews, photos and videos, digital sketches, map locations and other documents and media types. Notes replaces traditional IMAP-based syncing with iCloud, which offers better end-to-end encryption and faster syncing.

Safari

Safari in El Capitan lets users pin tabs for frequently accessed websites to the tab bar, similar to Firefox and Google Chrome. Users are able to quickly identify and mute tabs that play audio without having to search for individual tabs. Safari supports AirPlay video streaming to an Apple TV without the need to broadcast the entire webpage. Safari extensions are now hosted and signed by Apple as part of the updated Apple Developer program and they received native support for content blocking, allowing developers to block website components (such as advertisements) without JavaScript injection.

Spotlight

Spotlight is improved with more contextual information such as the weather, stocks, news and sports scores. It is also able to process queries in natural language. For example, users can type "Show me pictures that I took in Yosemite National Park in July 2014" and Spotlight will use that request to bring up the corresponding info. The app could now be resized and moved across the screen.

Photos

Photos introduced editing extensions which allows Photos to use editing tools from other apps.

System Integrity Protection

OS X El Capitan has a new security feature called System Integrity Protection (SIP, sometimes referred to as "rootless") that protects certain system processes, files and folders from being modified or tampered with by other processes even when executed by the root user or by a user with root privileges (sudo). Apple says that the root user can be a significant risk factor to the system's security, especially on systems with a single user account on which that user is also the administrator. System Integrity Protection is enabled by default, but can be disabled.

Reception

Upon release, OS X El Capitan was met with mostly positive reviews from both users and critics, with praise mostly going towards the overall functionality of the new features and improved stability. Dieter Bohn of The Verge awarded the operating system a score of 8.5 out of 10; while Jason Snell of Macworld was also positive, rating it 4.5 out of 5.

Issues

After the 10.11.4 update, many users started reporting that their MacBooks were freezing, requiring a hard reboot. This issue mostly affects Early 2015 MacBook Pro computers, although many others have reported freezes in other models. Several users created videos in YouTube which showed the freezes. Soon after this, Apple released the 10.11.5 update, which contained stability improvements. Apple later acknowledged these problems, recommending their users to update to the last point release.