Siri is a virtual assistant developed by Apple Inc. that interprets voice or typed requests to answer questions, control device functions, and take actions across apps, first appearing as a beta feature on the iPhone 4S on October 4, 2011. According to Apple’s launch announcement, iPhone 4S “introduces Siri, an intelligent assistant that helps you get things done just by asking,” initially in English, French, and German. Apple Newsroom.

Origins and acquisition

Siri began as a spin‑off from the Cognitive Assistant that Learns and Organizes (CALO) project at SRI International, a DARPA‑funded research effort to build a learning personal assistant; Siri, Inc. was founded by Dag Kittlaus, Adam Cheyer, and Tom Gruber to commercialize that work. CALO; Britannica.

The first Siri product was a free iPhone app released in February 2010 that let users make reservations, check listings, and perform local tasks by voice. Wired. Apple purchased Siri, Inc. in April 2010, a deal confirmed at the time by company representatives and board members. TechCrunch; MacRumors.

Launch and platform expansion

Apple integrated Siri into iOS 5 on the iPhone 4S in October 2011 and removed the earlier standalone app. Apple Newsroom; MacRumors. Siri later expanded across Apple platforms, including macOS with macOS Sierra in 2016, Apple TV’s Siri Remote (2015), Apple Watch (watchOS), and the HomePod smart speaker family. Apple Newsroom; Apple Newsroom; Apple Newsroom.

Technology and architecture

Early Siri deployments used Nuance Communications for speech recognition, a relationship publicly acknowledged by Nuance CEO Paul Ricci in 2013, while higher‑level interpretation and actions were handled by Apple. MacRumors.

Beginning with iOS 15 in September 2021, Apple moved many Siri requests to on‑device processing by default on supported hardware, enabling faster responses and some offline tasks. Apple Newsroom; MacRumors. In June 2024 Apple introduced Apple Intelligence—privacy‑preserving generative models running on device and, when needed, via Private Cloud Compute on Apple‑controlled servers—which also underpins a redesigned Siri with richer language understanding and product knowledge. Apple Newsroom.

Apple also confirmed that access to OpenAI’s ChatGPT is integrated into Siri and system writing tools on an opt‑in, per‑request basis. Apple Newsroom; CNBC. Some of Siri’s personal‑context and app‑action upgrades are scheduled to arrive in software updates following the initial iOS 18 release. MacRumors.

Features and capabilities

Siri supports device control (e.g., settings, timers, alarms), messaging and communication, media playback, navigation, and information queries, with expanding capabilities tied to Apple’s App Intents and SiriKit developer frameworks. Apple Developer. Apple’s 2024 update adds a new on‑screen design, the ability to type to Siri and switch fluidly between voice and text, and expanded product knowledge to answer thousands of “how to” questions about device features. Apple Newsroom.

Through SiriKit (introduced with iOS 10), third‑party apps in specific domains—such as messaging, payments, ride booking, VoIP calls, workouts, and photo search—can expose actions that Siri can perform. Apple Developer; Microsoft Xamarin Blog. After Apple acquired the Workflow automation app in 2017, the Shortcuts app (iOS 12, 2018) enabled users to trigger multistep automations by voice. TechCrunch; Wired.

Languages and internationalization

Siri supports numerous languages and regional variants across countries and services, with Apple publishing per‑feature availability. Apple Feature Availability. In India, Apple documents that Siri can recognize English mixed with several Indic languages when English (India) is selected. Apple Support.

Activation and interaction

Since iOS 17 (2023), users can activate Siri by saying “Siri” instead of “Hey Siri,” with both phrases supported and configurable in settings; Apple also added back‑to‑back requests without repeating the wake phrase. MacRumors; TechCrunch. In iOS 18, users can fluidly switch between speaking and typing to Siri. Apple Newsroom.

Privacy and data practices

Apple states that Siri does as much processing as possible on device, minimizes data sent to servers, and by default does not retain audio recordings unless a user opts in to “Improve Siri & Dictation.” Apple Newsroom; Apple Legal—Siri, Dictation & Privacy. In 2019, after reports about human “grading” of audio snippets, Apple suspended the program and relaunched it with changes: audio is off by default, review is opt‑in, and only Apple employees may review samples. TechCrunch; Apple Newsroom; CNBC.

In January 2025, Apple agreed to a $95 million settlement of U.S. class‑action claims alleging inadvertent Siri recordings; Apple denied wrongdoing and reiterated that Siri data is not sold or used to build marketing profiles. Reuters; AP News; MacRumors; The Verge.

Competition and ecosystem context

Siri is a core layer of iOS, iPhone, iPadOS, macOS, watchOS, tvOS, CarPlay, and HomePod, and it competes in the broader market of voice assistants alongside offerings embedded in smart speakers and phones. Apple’s HomePod line highlights Siri’s role in the home and integration with Apple Music and HomeKit. CNBC; Apple Newsroom.

Research lineage and naming

Siri’s research lineage traces to SRI International’s Artificial Intelligence Center and the DARPA‑backed CALO program, which produced several commercial spin‑offs including Siri. CALO; Wired. The name “Siri” has been publicly linked by the founders to Norwegian roots and company history. Britannica; The Washington Post.