Swift 5.5 Release Process

This post describes the release process, and estimated schedule for Swift 5.5.

Snapshots of Swift 5.5

Downloadable snapshots of the Swift 5.5 release branch will be posted regularly as part of continuous integration testing. As support is available, snapshot downloads will be added for newly supported platforms.

Once Swift 5.5 is released, the official final builds will also be posted in addition to the snapshots.

Getting Changes into Swift 5.5

On April 16, 2021 the release/5.5 branch will be cut in the swift repository and related project repositories. This will contain the changes that will be released in Swift 5.5. After the branch is cut, changes can be landed on the branch via pull request if they meet the criteria for the release.

Philosophy on Taking Changes into Swift 5.5

  • All language and API changes for Swift 5.5 will go through the Swift
    process. Evolution
    proposals should aim to be completed by the branch date in order to
    increase their chances of impacting the Swift 5.5 release. Exceptions
    will be considered on a case-by-case basis, particularly if they tie
    in with the core goal of the release.

  • Other changes (e.g., bug fixes, diagnostic improvements, SourceKit interface
    improvements) will be accepted based on their risk and impact.

  • Low-risk test tweaks will also be accepted late into the release branch if
    it aids in the qualification of the release.

  • As the release converges, the criteria for accepted changes will become
    increasingly restrictive.

Impacted Repositories

The following repositories will have a release/5.5 branch to track
sources as part of Swift 5.5 release:

The llvm-project will have a corresponding swift/release/5.5 branch.

Release Managers

The overall management of the release will be overseen by the following
individuals, who will announce when stricter control of change goes into
effect for the Swift 5.5 release as the release converges.

Platform Release Managers

Please feel free to post on the development forum
or contact Ted Kremenek directly concerning any questions about the release management

Pull Requests for Release Branch

In order for a pull request to be considered for inclusion in the release
branch (release/5.5) after it has been cut, it must include the following

  • Explanation: A description of the issue being fixed or enhancement being
    made. This can be brief, but it should be clear.

  • Scope: An assessment of the impact/importance of the change. For
    example, is the change a source-breaking language change, etc.

  • SR Issue: The SR if the change fixes/implements an issue/enhancement on

  • Risk: What is the (specific) risk to the release for taking this change?

  • Testing: What specific testing has been done or needs to be done to
    further validate any impact of this change?

  • Reviewer: One or more code owners
    for the impacted components should review the change. Technical review can
    be delegated by a code owner or otherwise requested as deemed appropriate or

All changes going on the release/5.5 branch must go through pull requests that are
accepted by the corresponding release manager.


Small typo here

Fixed, thank you.

Can I ask, what's the intended status of the Concurrency features in 5.5? The CHANGELOG makes mention of them, but the "Road to Swift 6" post said they would only ship in Swift 6. I would imagine whatever version of them exists at the branching point will stay behind the current compiler flag, with Swift 6 enabling it by default. Is that accurate?


I noticed there is no mention for swift-format, is still part of the Swift release process?


I suggest you read the Swift Concurrency Roadmap. There is actually a full description of which concurrency features will land in Swift 5:

As the roadmap points out, all the features placed in the first phase will be non-source breaking and possible to go into Swift 5.

The fact that the concurrency features will be compatible with Swift 5 initially says nothing about whether they'll actually be released as part of a Swift 5 release.


Is there any rough time frame when we can expect the release to happen? I've scoured the forums and the website, but I'm unsure how long after this post it takes to get the release released :)

Looking at the previous releases it's always either september or march, so prepare for six months of waiting

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According to the 'status' in various proposals I'm assuming many of the async proposals will be released as part of 5.5

Status: Implemented (Swift 5.5)

Yes, they're obviously in the compiler. The question, again, is whether they'll be exposed by default or whether we'll have to continue to use the compiler flag to enable them. Enabling them by default but calling the release Swift 5.5 seems to contradict the earlier Swift 6 timeline where it was stated that whatever release the concurrency features shipped in would be Swift 6.

There's also the question of whether Apple will support shipping apps using the concurrency features if they aren't enabled by default, but I don't expect them to say anything about that until WWDC.

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Judging by past releases I'd also speculate a beta in time for WWDC (June 7!), with official release mid September - mid October.

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I hope we will soon get an official comment on this. I'm highly interested if these features that are already implemented or will be complete soon will land for a normal swift 5.5 user or if only Apple is officially allowed to start using these features like it was with result builders last year.

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Yeah, same here. I‘m mostly hoping for async await and the continuations to be useable in apps asap. While the higher level concurrency stuff is exciting, I would guess this is really Swift 6 material.

What happened to 5.4? It’s unusual that a new version branch is announced before it’s predecessor is released, no?

That's part of Xcode 12.5 while Swift 5.5 will be part of Xcode 13.


Looking forward to see the next iteration of Swift never been exciting this much.

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Can anyone from core team/maintainers please provide us with a list of concurrency features split in three groups:

  1. Features that are going to be released in 5.5 (like async/await as IIRC it is cemented and scheduled for release, correct me if I'm mistaken)
  2. (if relevant) Features at risk of not being released in 5.5 (like actors that just got accepted)
  3. Features that will NOT be released in 5.5 (e.g. async let)

There are so many proposals, and more are branching off of existing ones, I'm actually lost :)


We should still be able to independently install Swift 5.5 as a CLI runtime.

You can download the toolchains from swift.org