Microsoft has accidentally leaked its internal “StagingTool” app that is used by employees to enable secret unreleased Windows 11 features. The software giant typically tests experimental or hidden Windows 11 features in public builds of the operating system, but Windows enthusiasts have until now had to rely on third-party tools to get access to secret features that Microsoft hasn’t yet enabled for all testers.

The accidental release of Microsoft’s StagingTool yesterday was part of the company’s “bug bash” event this week, where engineers encourage feedback from Windows 11 testers to squash any remaining bugs before a big update. Microsoft is expected to deliver its next big Windows 11 update in September, including native support for RAR and 7-Zip files.

Twitter user XenoPanther first discovered the StagingTool on Wednesday before Microsoft quickly removed it hours later. The internal tool is now being widely shared by the Windows community. StagingTool is very similar to the third-party ViveTool app that Windows enthusiasts have been using for years to enable hidden Windows 11 features.

StagingTool is a command line app that lets you toggle feature IDs that enable certain unreleased parts of Windows 11. It’s particularly useful for when Microsoft uses A/B testing for features, where only a small subset of Windows Insiders will get access to a feature before Microsoft rolls it out more broadly to testers.

Windows enthusiasts always look out for new features every time Microsoft releases a new build for testing. There are hidden flags in the operating system which enable features, allowing the Windows community to see what OS additions Microsoft is experimenting with before the company has even acknowledged the new features.

Microsoft is fully aware of the community enabling these secret features. “We also recognize that some of our more technical Insiders have discovered that some features are intentionally disabled in the builds we have flighted,” acknowledged Amanda Langowski, the lead for the Windows Insider Program, in a blog post last year.

Microsoft’s own StagingTool leak makes this process of enabling secret features even easier and more “official” given this is an internal tool that engineers use to test unreleased features.