Your iPhone Is Training Apple’s AI, but Not Spying… Right?

In a blog post published on April 14, Apple announced a new method to refine the performance of its large language models (LLMs), the engines behind Apple Intelligence. The goal is to deliver smarter features like better summaries, writing suggestions, and email recaps — while still maintaining Apple’s strong privacy stance.

Apple used to train its AI with made-up data that mimics real messages to avoid using personal info, but this often led to clunky or off responses. Now, Apple will let users’ devices compare AI-generated messages to real emails stored on the device without sending the actual emails anywhere. The device just tells Apple which AI result came closest, helping improve the system while keeping your data private.

If you’re concerned about privacy, Apple says not to worry. This new technique only applies to users who’ve opted in to share Device Analytics. Even then, Apple won’t access the actual content of your emails or messages.

Instead, your device handles the comparison between synthetic AI outputs and your actual content. It simply tells Apple which synthetic result is closest to your content. This gives Apple insight into broader trends and improves its AI models without touching your private data.

This update isn’t just about email. Apple is also using its privacy-focused AI training for features like Genmoji, where users create custom emojis with short prompts, and Writing Tools that help summarize or edit longer texts. For short prompts, Apple still uses differential privacy, a method that stops them from learning anything personal. But for longer text, they say smarter methods are needed, which is where synthetic data combined with on-device sampling comes in.

Apple’s move comes as the company races to catch up with AI developments from rivals like Google, Amazon, and Samsung. Despite being an early innovator with Siri, Apple has struggled to keep pace in the generative AI space. Internally, Apple executives have expressed frustration with Siri’s outdated capabilities. A recent reshuffle saw Vision Pro leader Mike Rockwell replace AI chief John Giannandrea as the head of Siri’s upgrades.