Jailbreak (iPhone OS)

iOS jailbreaking is privilege escalation for the process of removing software restrictions imposed by Apple on iOS and tvOS. It does this by using a series of kernel patches. Jailbreaking permits root access to iOS, allowing the downloading and installation of additional applications, extensions, and themes that are unavailable through the official Apple App Store.

iOS jailbreaking dates back to the original iPhone in July 2007 and has continued into the present day. Apple has responded with updates to iOS: patching exploits and upgrading hardware. Jailbreaking communities have not been legally threatened. The legal status of jailbreaking is unclear in most countries; while many prohibit tampering with digital locks, they tolerate jailbreaks that do not infringe on copyrights. In 2010, 2012, and 2015, the U.S. Copyright Office approved exemptions allowing smartphone users to jailbreak their devices.

Jailbreaking in general means breaking the device out of its "jail", a metaphor used in Unix-style systems, for example in "FreeBSD jail". A jailbroken iPhone, iPod Touch, or iPad running iOS can still use the App Store, iTunes, and other normal functions, such as making telephone calls. Furthermore, a jailbroken device can be reverted to a standard 'jailed' device by restoring the device in Recovery Mode, although any incompatible software installed while jailbroken will be wiped.

Jailbreaking is a form of privilege escalation, and describes privilege escalation on devices by other manufacturers as well.

One of the reasons for jailbreaking is to expand the feature set limited by Apple and its App Store. Apple checks apps for compliance with its iOS Developer Program License Agreement before accepting them for distribution in the App Store. However, their reasons for banning apps are not limited to safety and security and may be regarded as arbitrary and capricious. In one case, Apple mistakenly banned an app by a Pulitzer-Winning cartoonist because it violated its developer license agreement, which specifically bans apps that "contain content that ridicules public figures." To access banned apps, users rely on jailbreaking to circumvent Apple's censorship of content and features. Jailbreaking permits the downloading of programs not approved by Apple, such as user interface customization and tweaks.

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