iOS 27 Arrives With Siri AI and New Developer Tools

Apple is making iOS 27 available starting September 14, bringing its redesigned Siri AI experience, new artificial intelligence features across built-in apps, and a new Foundation Models framework for developers. The release also changes what developers can build directly into iPhone apps, making this more than a visual update to Apple's mobile operating system.

iOS 27 puts Siri AI at the center of the update

The most visible change is Siri AI, Apple's expanded assistant powered by Apple Intelligence. Apple says users can interact with Siri naturally by typing or speaking, while the assistant can provide richer answers and help with tasks such as planning and working with information. The company says Siri AI is rolling out in English initially, so the experience will not be identical across every language or region on launch day.

That distinction matters because Apple is not simply giving the existing Siri interface a new appearance. The company is positioning Siri AI as a broader assistant that can understand more context and perform more useful work. Some capabilities depend on the device and region, however, so the feature list shown on Apple's iOS 27 page should not be treated as a guarantee that every iPhone receives every artificial intelligence feature.

Apple is also changing what developers can build with iOS 27

For developers, one of the most consequential additions is the Foundation Models framework, a native Swift programming interface for working with language models inside apps. Apple says developers can use its on-device Foundation Models as well as other models that conform to Apple's Language Model protocol. That gives app developers a way to add language-model capabilities without designing an entirely separate artificial intelligence infrastructure for every application.

The framework also supports multimodal prompts, meaning an application can provide images alongside text for model processing. Apple's documentation describes tools for tasks such as optical character recognition, which extracts text from images, and barcode recognition. Developers can also use Dynamic Profiles to change models, tools, and instructions during an ongoing session, giving applications more control over how an artificial intelligence feature behaves.

The new model changes mean developers need to retest their apps

There is a less obvious consequence for developers who already use Apple's Foundation Models. Apple says the on-device model changes when users update to iOS 27 and the corresponding new operating systems. That means an application that behaved correctly against an earlier model should not simply assume identical output after the operating-system upgrade.

This is particularly relevant for applications that depend on structured responses, tool calling, or tightly controlled prompts. Apple recommends testing prompts against the new model, and its developer documentation describes changes to model behavior and error handling. For production applications, that makes model regression testing part of the iOS 27 upgrade rather than an optional check after release.

Apple is extending AI beyond Siri

iOS 27 also spreads Apple Intelligence into several ordinary phone functions. Apple highlights new photo-editing capabilities including Spatial Reframing and an upgraded Clean Up feature, while the Home app can group related activity notifications and use artificial intelligence to search supported HomeKit Secure Video footage by describing what happened.

Maps is also gaining an enhanced Flyover experience that combines aerial imagery with Visual Intelligence models to represent details such as buildings and individual trees. These features show Apple's broader strategy: artificial intelligence is becoming a layer underneath multiple applications rather than a feature that exists only inside a chatbot-style assistant.

The update supports a wide range of older iPhones

Apple's compatibility list extends iOS 27 back to the iPhone 11 and the second-generation iPhone SE. It also includes the iPhone 12, 13, 14, 15, 16 and 17 families, along with newer models such as iPhone Air, iPhone 17e and the latest iPhone models.

Compatibility with iOS 27 does not mean every supported iPhone receives every Apple Intelligence capability. Apple's feature availability depends on hardware, language, and region, so owners of older compatible devices should expect a smaller feature set than users of newer hardware. This distinction is especially important for artificial intelligence features that require newer processing capabilities.

The software release is arriving alongside Apple's new developer stack

Apple released the iOS 27 Release Candidate to developers on September 9, identified as build 24A435, ahead of the public availability date. Xcode 27 Release Candidate was also released the same day, giving developers the corresponding development environment and software development kit needed to prepare applications for the new operating system.

Apple has already opened App Store submissions for apps built against the new operating-system releases. For developers, the timing means the transition is not starting on September 14: the tools and release candidate have already been available, and applications can be submitted ahead of the customer rollout.

iOS 27 is a bigger developer change than its interface suggests

The redesigned interface will be the part most users notice first, but the Foundation Models framework may have the longer-term effect on software. Developers can now build applications around an operating-system-provided language model, multimodal input, tool calling, and model-selection mechanisms rather than treating artificial intelligence as an isolated web service.

That also creates a new responsibility. Applications that depend on model output need testing across operating-system releases, devices, languages, and feature availability instead of assuming that an artificial intelligence response is as deterministic as a traditional software function. As iOS 27 reaches users on September 14, developers who treat the update as both an operating-system release and a model-platform change will be better positioned to catch those differences before they become production bugs.