What's new in Swift: December 2025 Edition

Tim Sneath

Dave Lester

December 19, 2025

Welcome to the latest digest of news from the Swift project.

Each edition, we share updates that we hope will be useful to you whether you’re writing code with Swift or contributing to the language as a whole, and we start with an introduction from this edition’s guest contributor:

As we near the end of the year, it’s a time for reflection and gratitude. We’re profoundly grateful for the energy, creativity, and dedication of our community: the hundreds of contributors who submit code to improve Swift, those who create and steward ecosystem packages with thoughtfulness, and the developers building remarkable things with this language.

Indeed, it has been a monumental twelve months for Swift as an open source project.

From its relatively humble roots as an open source project, starting with a simple blog post ten years ago this month, the Swift project now comprises over 70 repositories, with hundreds of contributors every week bringing fresh perspectives, performance improvements, and tooling enhancements to the ecosystem.

The release of Swift 6.2 brings more approachable concurrency with defaults that align with a philosophy of progressive disclosure: making advanced features available when you need them, but keeping them out of your way when you don’t. Swift 6.2 also adds WebAssembly support, deep C++ interoperability, and improved memory safety features.

This year proved that Swift truly runs everywhere, across a variety of platforms and use cases:

Embedded: Embedded Swift is rapidly evolving, moving from experimental to practical use cases, with significant updates targeted for the upcoming 6.3 release.

Android: The workgroup is making strides with daily snapshot builds and end-to-end demos, bringing native Swift development closer to reality on Android devices.

Windows: Support is maturing fast, with richer tooling via the VS Code extension and a growing library of packages that support Windows out of the box.

BSD: The preview of Swift on FreeBSD support is now available for FreeBSD 14.3 and later, and will be featured in a FOSDEM 2026 talk about Porting Swift to FreeBSD.

AI: The ecosystem is evolving quickly, with MLX providing a Swift-friendly API for machine learning on Apple Silicon, and numerous packages from Hugging Face for Swift development.

Server: Backend development remains a major growth area. At the recent AWS re:Invent conference, Amazon announced integrated support for Swift in Amazon Linux and adoption of the AWS Lambda Runtime, signaling that the cloud is ready for Swift’s memory safety and speed.

And of course, Swift remains the unrivaled language of choice for building apps across all Apple platforms, whether you’re building an app or a game for iPhone, iPad, Mac, Apple Watch, Apple TV, or Apple Vision Pro!

So thank you, once more, on behalf of all of us working on Swift: there would be no Swift community without you!

— Tim Sneath

To end this milestone year, let’s take a look at some of the things that caught our attention this month.

Swift at FOSDEM 2026

Get ready for FOSDEM, the world’s largest independently run open source conference, taking place in Brussels in late January / early February. The Swift community will be there, with a Pre-FOSDEM Community Event. The Call for Proposals is open for short talk submissions through January 5th, 2026 (23:59 CET).

Outside of the pre-conference event, Swift talks will appear in several FOSDEM devrooms including Containers, BSD, LLVM, and SBOMs. Hope to see you there!

Talks worth watching

Beyond Web Services: Swift for Low-Level Container infrastructure - Eric Ernst introduces us to Apple’s Containerization and Container open source projects, built entirely in Swift.
Separate code from configuration with Swift Configuration - Swift Configuration provides a unified approach to handling configuration in your Swift applications. For more information, also check out the Swift Configuration 1.0 announcement from last week.
Getting started with gRPC Swift - A deep dive into the Swift package for gRPC, a key building block of performant cloud services.

Behind the scenes interviews

Running Swift in AWS Lambda | Serverless Office Hours - Sebastien Stormacq answered developer questions and was live coding with Swift on AWS Lambda. Also check out the related Swift AWS Lambda Runtime package.
Observability in Server Side Swift, with Moritz Lang - Dev Conversations #16 - This interview covers all things distributed tracing and Swift OTel.
Code-along: Start building with Swift and SwiftUI - Originally live streamed, a developer code-along that walks you through building a complete iOS interface using Swift and SwiftUI, followed by a Q&A session to answer developer questions.

Swift blog highlights

In case you missed it, here are several recent blog posts you’ll want to check out:

Exploring the Swift SDK for Android - Common questions about Swift on Android are answered by the Android workgroup, and new Swift 6.3 SDK nightly previews were announced.
Temporal Swift SDK introduced - Temporal has also blogged about using Swift with Temporal.
2025 Google Summer of Code contributors had posts featuring work related to several Swift-related projects, everything from Bringing Swiftly support to VS Code, Extending Swift-Java Interoperability, Improved code completion for Swift, and Improved console output for Swift Testing.

Swift everywhere

As this month’s guest contribution shared, Swift continues to expand to new platforms. Here are a few recent examples from the community:

Using Swift SDKs with Raspberry Pi - Did you know Swift can run on a Raspberry Pi? This blog post does a deep dive, it’s time to open your terminal and follow along!
Swift for WASM December 2025 updates - An update on progress related to Swift for WASM. In December the community also had an online meetup including talks.
AWS blog post about AWS Lambda runtime - The Swift AWS Lambda Runtime moved to the official AWS Labs GitHub organization, delivering a vendor-supported approach to running Swift on AWS Lambda.
Swift on a Pebble watch - A fun example of how a developer used Swift’s embedded support to build a “hello world” example on a 10-year-old Pebble Time Round watch.

Swift Evolution

The Swift project adds new language features to the language through the Swift Evolution process. These are some of the proposals currently under discussion or recently accepted for a future Swift release.

Under Active Review:

SE-0501 HTML Coverage Report - This proposal adds HTML coverage report generation to Swift Package Manager’s swift test command. Currently, SwiftPM only generates JSON coverage reports, which are useful for automated tools but difficult for developers to read directly. The new --coverage-format option would allow generating HTML reports alongside or instead of JSON, enabling visual inspection in CI systems and faster feedback during development.

Recently completed:

SE-0497 Controlling function definition visibility in clients - The @inlinable attribute in Swift allows function definitions to be visible to callers, enabling optimizations like specialization and inlining. This proposal introduces explicit control over whether a function generates a callable symbol and makes its definition available for optimization purposes.
SE-0493 Support async calls in defer bodies - Swift’s defer statements provide scope-based cleanup but currently cannot perform asynchronous work, forcing developers to either manually insert cleanup on every exit path or spawn detached tasks. This proposal allows await calls within defer bodies when the enclosing context is async, with the defer statements implicitly awaited at scope exit to ensure proper cleanup completion.

Editor Note: With this update, we’re going to take a break from the blog for the next couple of weeks. Wishing everyone a restful end to 2025!

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