What's New in macOS 27.3 Beta 1
This beta release includes several updates primarily aimed at developers, with new features for app subscriptions and improvements in system functionality. Users will notice changes once developers implement these updates in their apps.
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New subscription options for apps
Customers can now buy multiple seats for auto-renewable subscriptions and invite others to join. This feature will be available once app developers adopt it.
Multiseat subscriptions let a customer purchase multiple seats for an auto-renewable subscription and invite others to join it. Check whether a subscription supports multiseat purchases through the new supportsMultiSeatPurchase property on Product and AdvancedCommerceProduct, which reflects the setting you configure in App Store Connect.
Apple's own words, from the StoreKit section of the notes
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Support for software controllers
The system now allows for software controllers, which can manage data without creating certain mappings. This change is relevant for developers creating specific applications.
SCSIControllerDriverKit now supports software controllers. A software controller declares itself by setting kIOPropertySoftwareIOKey (an OSBoolean, from <IOKit/storage/IOStorageControllerCharacteristics.h>) through UserSetHBAProperties(). The system honors this setting only before controller initialization completes, so it stays fixed for the life of the controller. Such a controller doesn’t create any DMA mappings, and your dext can access the data buffer associated with a particular I/O through the UserCopyDataBuffer API.
Apple's own words, from the SCSIControllerDriverKit section of the notes
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Automatic key management for services
The system will now manage unused evaluation keys for certain services automatically, which may enhance how apps interact with network filters once developers update their services.
The system now keeps a set of unused evaluation keys uploaded to your NEURLFilter PIR service, and when it runs out of pre-uploaded keys, it automatically falls back to sending a fresh evaluation key inline with the query. When a query includes an evaluation key, your service must use it directly instead of looking one up by the user identifier.
Apple's own words, from the NEURLFilter section of the notes
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Booting improvements for Linux
A fix has been made for users booting Linux on specific Mac models, ensuring that multiple cores are available during the boot process.
Fixed: Only a single core is available when you boot Linux or other third-party operating systems from a custom raw boot object on Mac computers with M5 Pro, M5 Max, and M5 Ultra chips.
Apple's own words, from the mBoot section of the notes
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Fix for in-app purchase errors
An issue has been resolved where users could incorrectly unbundle subscriptions in certain scenarios, ensuring a smoother purchasing experience in apps.
Fixed: Making an in-app purchase for a subscription that is a member of a subscription bundle incorrectly allows the user to unbundle instead of throwing an error.
Apple's own words, from the StoreKit Testing in Xcode section of the notes
Summarised by us from macOS 27.3 Golden Gate Beta Release Notes on November 4, 2026. Each point cites the area of Apple's notes it came from, and nothing is included that Apple did not publish.
That is our plain-English reading of Apple's release notes for this build, which cover 9 areas of the system — 4 new features, 3 resolved issues, 2 known issues, 6 deprecations. Every point above traces back to an item Apple published; we translate the notes, we do not add to them. Apple's own wording, in full and unedited, follows below.
Those notes are written for developers, so they describe frameworks, APIs and fixed bugs rather than consumer features. That makes them the most precise record of what actually changed in this build — and the reason a fix you noticed may be listed under the framework responsible rather than under the app you saw it in.
DriverKit1 New Features1 Deprecations
New Features
- DriverKit 27.3 adds IOUserSCSIParallelInterfaceController::UserCopyDataBuffer, which supersedes the deprecated UserGetDataBuffer and has the same API interface. UserCopyDataBuffer returns the buffer at +1, so you must release it when you finish.
Deprecations
- IOUserSCSIParallelInterfaceController::UserGetDataBuffer is deprecated in DriverKit 27.3 because it leaks memory. Use UserCopyDataBuffer instead. UserCopyDataBuffer returns the buffer at +1, so you must release it when you finish.
mBoot1 Resolved Issues
Resolved Issues
- Fixed: Only a single core is available when you boot Linux or other third-party operating systems from a custom raw boot object on Mac computers with M5 Pro, M5 Max, and M5 Ultra chips.
NEURLFilter1 New Features3 Deprecations
New Features
- The system now keeps a set of unused evaluation keys uploaded to your NEURLFilter PIR service, and when it runs out of pre-uploaded keys, it automatically falls back to sending a fresh evaluation key inline with the query. When a query includes an evaluation key, your service must use it directly instead of looking one up by the user identifier.
Deprecations
- NEURLFilter no longer supports user tiers. The system no longer calls your service’s /token-key-for-user-token endpoint and instead uses the first valid public key in your Privacy Pass token issuer directory.
- NEURLFilter now limits a service’s PIR configuration to at most 65,536 shards and requires the shard count to be a power of two, for example, 256, 512, 1024, or 2048. The system rejects a configuration that exceeds the limit or whose shard count isn’t a power of two. Configurations that already meet both constraints work with earlier releases and need no changes.
- Your NEURLFilter service URL and Privacy Pass issuer URL must now be declared statically in your app’s Info.plist, and providing them only at runtime is deprecated. Add an NSPIRConfiguration dictionary to your app’s Info.plist (not the URL filter extension’s) with a PIRServerURL key and a PrivacyPassIssuerURL key. PIRServerURL corresponds to pirServerURL, and PrivacyPassIssuerURL corresponds to pirPrivacyPassIssuerURL and defaults to PIRServerURL when absent. Each value should contain only the host name of your server. If you also set these values at runtime, they must match the Info.plist values exactly, or the system fails to start the filter with an invalid configuration error.
Rosetta2 Deprecations
Deprecations
- macOS now notifies users when an audio plug-in or print dialog extension that requires Rosetta is used, and lists these plug-ins in the Intel-based apps list in General settings. To avoid the notification, check with the developer for an Apple silicon version of the plug-in or extension.
- macOS now notifies you when you print using a printer driver that requires Rosetta but is not yet updated for Apple silicon. macOS also prompts you to install Rosetta if it isn’t already installed. To avoid notifications, use AirPrint, which is built into most printer models and requires no additional driver installation, or contact the driver developer to learn whether an update for Apple silicon is available or planned.
SCSIControllerDriverKit1 New Features
New Features
- SCSIControllerDriverKit now supports software controllers. A software controller declares itself by setting kIOPropertySoftwareIOKey (an OSBoolean, from <IOKit/storage/IOStorageControllerCharacteristics.h>) through UserSetHBAProperties(). The system honors this setting only before controller initialization completes, so it stays fixed for the life of the controller. Such a controller doesn’t create any DMA mappings, and your dext can access the data buffer associated with a particular I/O through the UserCopyDataBuffer API.
Siri1 Known Issues
Known Issues
- On macOS, Siri cannot find app entities donated to Spotlight by third-party apps unless those entities conform to a schema.
Speech1 Resolved Issues
Resolved Issues
- Fixed: An assertion failure occurs when you use CaptureInputSequenceProvider in a “Mac (Designed for iPad)” target.
StoreKit1 New Features
New Features
- Multiseat subscriptions let a customer purchase multiple seats for an auto-renewable subscription and invite others to join it. Check whether a subscription supports multiseat purchases through the new supportsMultiSeatPurchase property on Product and AdvancedCommerceProduct, which reflects the setting you configure in App Store Connect.
StoreKit Testing in Xcode1 Resolved Issues1 Known Issues
Resolved Issues
- Fixed: Making an in-app purchase for a subscription that is a member of a subscription bundle incorrectly allows the user to unbundle instead of throwing an error.
Known Issues
- When you launch an app that uses SKTestSession for the first time, some StoreKit Test API calls might hang. Workaround: Set a StoreKit configuration file in your scheme’s run options, then rerun the tests.
Source: macOS 27.3 Golden Gate Beta Release Notes, Apple Developer Documentation. Captured when this build was current — Apple replaces that page with each new beta.
What macOS 27.3 Beta 1 Is
macOS 27.3 Beta 1 is build 26C5035r, released on November 3, 2026. It is a pre-release build available through the developer and public beta channels, and it supersedes every earlier macOS 27.3 beta.
This is the first build of the macOS 27.3 cycle we have on record, which makes it the baseline every later build is measured against.
Beta 1 Build Numbers Across Every Platform
Apple ships each beta wave across its platforms on the same day, usually with different build numbers per operating system. Here is every build we recorded in this wave, taken from Apple's own release feed rather than reposted from elsewhere.
Matching build numbers between two platforms — as iOS and iPadOS almost always have — mean they are built from the same source, which is why their betas behave identically.
| Platform | Version | Build | Released |
|---|---|---|---|
| iOS 27 | 27.3 | 24C5037i | November 3, 2026 |
| iPadOS 27 | 27.3 | 24C5037i | November 3, 2026 |
| macOS 27 | 27.3 | 26C5035r | November 3, 2026 |
| tvOS 27 | 27.3 | 24K5286g | November 3, 2026 |
| visionOS 27 | 27.3 | 24N5286r | November 3, 2026 |
| watchOS 27 | 27.3 | 24S5284h | November 3, 2026 |
How to Install macOS 27.3 Beta 1
There is no profile to download. Enrol your Apple Account free at beta.apple.com for the public beta or developer.apple.com for the developer channel, then open System Settings → General → Software Update → Beta Updates and select the macOS 27.3 channel. The build appears in Software Update like any ordinary update.
If you are already on an earlier macOS 27.3 beta, this arrives as a normal update and no re-enrolment is needed. Our full macOS 27.3 install guide covers the process step by step, and our device pages tell you whether your exact model qualifies.
Should You Install It?
That depends on where this build sits in the cycle and what the device is for. Early builds break third-party apps — banking and workplace apps first — and cost you a week of heavy background indexing. Later builds are progressively calmer.
Whatever you decide, make an archived backup on a computer first. A backup made on macOS 27.3 cannot be restored onto the previous release, so it is the only route back with your data intact — our backup guide explains the difference, and our honest assessment covers running a beta on the phone you depend on.
What Comes After Beta 1
Beta 1 is the newest macOS 27.3 build we have on record. Based on this cycle's cadence, the next one is due within the next couple of weeks — this page updates automatically when it lands.
Our build history tracks every macOS build with its date and the gap before it, which is the clearest picture of how a cycle is progressing. The beta calendar guide explains the shape of the year.
Frequently Asked Questions
What's new in macOS 27.3 Beta 1?
This beta release includes several updates primarily aimed at developers, with new features for app subscriptions and improvements in system functionality. Users will notice changes once developers implement these updates in their apps. The changes Apple documented include new subscription options for apps, support for software controllers, automatic key management for services.
What are the known issues in macOS 27.3 Beta 1?
Apple lists 2 known issues for this build across 2 areas of the system, with workarounds where one exists. They are listed in full on this page under each area.
Should I install macOS 27.3 Beta 1?
Not on a device you depend on. Betas break third-party apps — banking and workplace apps first — and cost battery life while the system re-indexes. If you have a spare device, or you accept restoring from scratch, it is reasonable. Back up to a computer first.
Does macOS 27.3 Beta 1 fix battery drain?
Heavy battery use in the first few days after any beta update is normal and comes from background re-indexing, not from a fault. It usually settles within 48 hours. Apple's notes for this build do not single out battery life; anything genuinely fixed is listed on this page under the framework responsible.
What is the build number for macOS 27.3 Beta 1?
macOS 27.3 Beta 1 is build 26C5035r, released on November 3, 2026.
When was macOS 27.3 Beta 1 released?
November 3, 2026.
Is there a beta profile for macOS 27.3 Beta 1?
No. Apple removed beta profiles in 2023. Enrol your Apple Account free at beta.apple.com or developer.apple.com and select the channel in Settings — there is no file to download.
How do I check which build I am on?
Settings → General → About, then tap the version number to reveal the build. If it reads 26C5035r you are on macOS 27.3 Beta 1. Our build number guide explains how to read them.
