Windows 10 Dev Channel has been designed for “highly technical users.” When using this channel from the Windows Insider Program, you’ll receive builds that are rough and contain code that is still in development. These builds won’t be stable. You’ll come across errors and problems, and you may have to resource to workarounds that may affect your experience.

Previews on the Dev Channel are not attached to any specific release of Windows 10. Instead, this channel’s features and changes will appear in future releases when they’re ready, and they are not tied to any specific release of Windows 10.

Windows 10 21H1 new features, changes, and related content can be found here.