Apple explains 'Siri's privacy protection features,' processing offline whenever possible and minimizing data collection

Apple has long been committed to protecting user data, and Apple products and services are designed and built with innovative privacy technologies and methods in mind. This also applies to Siri, the voice recognition assistant available on Apple devices. Apple has explained on its official website how Siri is committed to privacy in particular.

Apple's long-standing privacy commitment to Siri - Apple (UK)

https://www.apple.com/jp/newsroom/2025/01/our-longstanding-privacy-commitment-with-siri/

Siri processes as much of the data as possible on the device
To protect user privacy, Siri is designed to do as much processing as possible directly on the user's device. No personal information is sent to Apple servers for analysis, but on-device processing alone enables a personalized experience.

When a user speaks or types to Siri, their request is processed on-device wherever possible. For example, when a user asks Siri to read unread messages or when Siri provides suggestions through a widget or Siri Search, the processing occurs on the user's device and the content of the message is not transmitted to Apple's servers. On supported devices, voice requests are processed entirely on-device using the Neural Engine unless the user chooses to share them with Apple.

The amount of data collected for Siri requests is kept to a minimum
While Apple tries to do as much processing as possible on the device, some features require real-time input from Apple servers. In those cases, Siri handles as little data as possible to provide accurate results. However, Siri searches and requests are not linked to the user's Apple account. During data processing, a random identifier (a long string of letters and numbers tied to one device) is used to track it, and no Apple account or phone number is used to identify the user's identity. Apple describes this process as 'unique among digital assistants in use today.'

Additionally, Apple won't store voice recordings of your interactions with Siri unless you explicitly opt-in to help improve Siri, and if it does, the recordings will only be used for that purpose and you can easily opt-out at any time.

◆ Breakthrough privacy protection through private cloud computing
Siri will be upgraded with Apple Intelligence , which, like everything else, is designed to protect user privacy every step of the way, and many of the models used are designed to run entirely on-device.

When you need access to larger models, Private Cloud Computing extends the privacy and security of your iPhone to the cloud, enabling even more intelligence. When Siri uses Private Cloud Computing, your data is not stored by or accessed by Apple, and Private Cloud Computing only uses your data to fulfill your request.

For more details about the private cloud computing used for Apple Intelligence, see the following article:

Apple explains its efforts to ensure the security of the AI processing server 'Private Cloud Compute' used in Apple's assistant AI 'Apple Intelligence' - GIGAZINE

In addition, Apple explained that 'Siri data has never been used to create profiles for marketing purposes, has never been given to users for advertising, or sold to anyone for any purposes. Apple is constantly developing technology to further protect Siri's privacy.'