Native UI Automation for Windows in Chromium

Benjamin Beaudry
Benjamin Beaudry
X LinkedIn

Published: August 14, 2025

From Chrome 138, Chromium-based browsers on Windows enable native UI Automation (UIA) support by default. UIA is the modern accessibility framework for Windows, used by assistive technologies like Narrator, Magnifier, and Voice Access.

Today, assistive technologies that use Microsoft Active Accessibility (MSAA) or IAccessible2 (IA2) connect directly to Chromium, which fully controls the accessibility data it receives–and that's not changing. Until now, UIA had to go through a Windows-managed emulation layer, a "middleman" that translated Chromium's MSAA data into UIA. This added latency, reduced reliability, and introduced compatibility issues for UIA-based tools.

In the top row, MSAA/IA2-based assistive technology communicates directly with Chromium using MSAA or IA2. In the bottom row, UIA-based assistive technology sends data using the UIA framework to a UIA emulation layer, which then communicates with Chromium using MSAA.
The accessibility stack before native UI Automation support in Chromium.

By implementing UIA natively, we've removed that proxy layer entirely–improving performance, increasing reliability, and simplifying the accessibility stack. Assistive technologies can now communicate directly with Chromium's accessibility engine.

In the top row, MSAA/IA2-based assistive technology still communicates directly with Chromium using MSAA or IA2. In the bottom row, UIA-based assistive technology now communicates directly with Chromium using UIA, without going through an emulation layer.
The accessibility stack after native UI Automation support in Chromium.

What this means for developers and users

  • UIA-based tools now deliver faster, more reliable performance. For example, Voice Access now fully works across all Chromium-based browsers.
  • The accessibility stack is simpler and fully owned by Chromium engineers, giving us direct ownership of the accessibility surface and making it faster to ship fixes and improvements independently of Windows updates.

This milestone reflects years of close collaboration between the Microsoft Edge and Google Chrome teams, bringing together deep engineering changes, extensive testing, and a shared goal of improving accessibility for everyone on Windows. We're also grateful to the NVDA and JAWS teams, who have partnered with us over the years to troubleshoot and fix UIA-related issues in Chromium.

Enterprise compatibility

If your environment depends on legacy behavior, you can temporarily revert to the old mode using the UiAutomationProviderEnabled policy. This policy will be supported through Chrome 146, giving organizations time to validate and update their tools.

Report issues

Native UIA support is now in Chromium-based browsers, and we want your feedback. If you develop or manage accessibility tools, test them with the latest Chromium builds and report any issues with the new UIA implementation.