Apple’s next-generation AI dictation feature for iPhone 17 Pro and iPhone Air is not enabled by default in the first developer beta of iOS 27.
Apple says the new AI-based dictation system offers “a major improvement in accuracy,” with more reliable capitalization and on-the-fly punctuation than the existing dictation system. The feature runs on Apple’s new AFM 3 Core Advanced model, which is a 20 billion parameter natively multimodal system that uses a sparse architecture, activating only one to four billion parameters at a time depending on demand.
To fit such a large model to a smartphone, the entire model is stored in flash rather than DRAM, with a lightweight routing block selecting a fixed set of “experts” during initial processing and periodically reselecting them during generation, a technique Apple calls following-instruction pruning.
In side-by-side human evaluations against Apple’s previous production dictation system across seven quality dimensions, AFM 3 Core Advanced was preferred for overall quality by a margin of 44.7% to 17.6%, with this preference being consistent across the other six dimensions, which include punctuation, capitalization, layout, capturing meaning, handling disfluencies, and style.
Due to the size of the model, the Dictation upgrade is limited to a handful of newer devices: the iPhone 17 Pro and iPhone 17 Pro Max, the iPhone Air, the Vision Pro with an M5 chip, iPads with an M4 chip or later with at least 12 GB of RAM, and Macs with an M3 chip or later with at least 12 GB of RAM. Notably, the standard iPhone 17 is excluded, as it comes with 8GB of RAM instead of the 12GB required by the larger model. The same AFM Core Advanced model also powers Apple’s new expressive and customizable Siri voices, another opt-in preview from Beta 1.
The new dictation model works entirely on the device, so transcription quality remains the same whether the iPhone is connected to a network or not. It’s unclear whether preview will remain disabled by default when iOS 27 is officially released later this year, or if Apple will automatically enable it at some point during the beta cycle this summer.
