Windows 11 25H2 multiclient midi

Just ran across this post. The information above is only partially correct.

Existing apps using WinMM MIDI 1.0 or WinRT MIDI 1.0 get multi-client for free with the new Windows MIDI Service.

However, Windows MIDI Services is not yet available in Windows itself. We're still fixing some last bugs that have been brought to us from partners.

The recent info that it is in 25h2 is a mistake on our part. It will not work yet on 25h2. Instead, it will be coming as a Windows Update.

Pete

Hello Roberto Tafuro,

Welcome to Microsoft Q&A.

Thank you very much for raising this insightful question about multi-client MIDI support in Windows 11. The information and observations you’ve provided are both accurate and forward-thinking. We completely understand your desire to use a single MIDI device across multiple applications simultaneously — this is indeed a common pain point in professional music production workflows.

Allow me to explain the current situation in more detail.

The information you’ve found regarding Windows 11 supporting multi-client MIDI is absolutely correct. Microsoft is actively working on this capability through a new architecture called Windows MIDI Services — a modern, scalable platform designed to replace the long-standing legacy MIDI system in Windows.

However, for this functionality to work as expected on your device, two key conditions need to be met — and these are likely the reasons why you’re still encountering limitations:

1. Operating System Support

• The new Windows MIDI Services is currently in public preview.
• As you’ve already noted, this feature was first introduced to public testers in Windows 11 Insider Preview Build 27788 (Canary Channel). Source: Announcing Windows 11 Insider Preview Build 27788 (Canary Channel) | Windows Insider Blog
• This means the feature is not yet implemented in any publicly released stable version of Windows 11. It remains in the Insider Program for thorough testing and refinement before being rolled out to all users in a future release.

2. Application-Level Support (The Most Critical Part)

• Currently, almost all Digital Audio Workstations (DAWs) and MIDI tools on the market — including those you mentioned such as Ableton Live and Midi Fighter Utility — are built on the legacy Windows MIDI API (WinMM).
• This older API was designed with an exclusive access model, meaning a MIDI device can only be accessed by one application at a time.
• Even if your system supports the new architecture, applications must be explicitly updated by their developers to use Windows MIDI Services.
• Until developers of tools like Ableton or Midi Fighter Utility release versions that specifically support Windows MIDI Services, these applications will continue to use the legacy connection model and therefore remain subject to the same single-client limitations.

Achieving true multi-client MIDI support requires a collaborative upgrade between the operating system and the software ecosystem. We are currently in the first phase of this transition: Microsoft has built and released the foundational platform to developers. The next step is for music software vendors to adopt it and integrate support into their applications.

We recommend keeping an eye on future Windows update announcements and on the official release notes of the music software you use (such as Ableton or Midi Fighter Utility). When support for this feature is added, it will likely be highlighted as a major improvement. You may also consider submitting feedback or feature requests to those software developers — this helps them understand user demand and may accelerate development priorities.

In the meantime, until native support becomes widespread, you may continue to use third-party virtual MIDI routing tools (like loopMIDI, Bome MIDI Translator, etc.) as a temporary workaround for forwarding MIDI signals between multiple applications.

We fully understand your anticipation for this long-awaited feature, and we believe the relevant teams are actively working towards its implementation. Multi-client MIDI is a crucial step toward enhancing the professional creative experience on Windows.

For reference:

Flight Hub – Windows Insider Program | Microsoft Learn

(Note: The 25H2 build based on 26200 may differ from 27xxxx builds where this feature was first introduced.)If your system is still on 26200, I recommend updating to a supported Insider build and checking the support status of the relevant software.

Thank you for your understanding and continued support. We hope the above information has been helpful. If you have any further questions, please don’t hesitate to contact us again.

Best wishes

Kai Ho | Microsoft Q&A Support Specialist