Siri ('siːri,_ˈsɪri ) is a virtual assistant that is part of Apple Inc.'s iOS, iPadOS, watchOS, macOS, tvOS, audioOS, and visionOS operating systems. It uses voice queries, gesture based control, focus-tracking and a natural-language user interface to answer questions, make recommendations, and perform actions by delegating requests to a set of Internet services. With continued use, it adapts to users' individual language usages, searches, and preferences, returning individualized results.
Siri is a spin-off from a project developed by the SRI International Artificial Intelligence Center. Its speech recognition engine was provided by Nuance Communications, and it uses advanced machine learning technologies to function. Its original American, British, and Australian voice actors recorded their respective voices around 2005, unaware of the recordings' eventual usage. Siri was released as an app for iOS in February 2010. Two months later, Apple acquired it and integrated it into iPhone 4S at its release on 4 October 2011, removing the separate app from the iOS App Store. Siri has since been an integral part of Apple's products, having been adapted into other hardware devices including newer iPhone models, iPad, iPod Touch, Mac, AirPods, Apple TV, and HomePod.
Siri supports a wide range of user commands, including performing phone actions, checking basic information, scheduling events and reminders, handling device settings, searching the Internet, navigating areas, finding information on entertainment, and being able to engage with iOS-integrated apps. With the release of iOS 10 in 2016, Apple opened up limited third-party access to Siri, including third-party messaging apps, as well as payments, ride-sharing, and Internet calling apps. With the release of iOS 11, Apple updated Siri's voice and added support for follow-up questions, language translation, and additional third-party actions.
iOS 17 enabled users to activate Siri by simply saying “Siri”, while the previous command, “Hey Siri”, is still supported.