Chromium-based browsers offer a number of accessibility-related features. When you visit
about:accessibility, you can see more about the state of these features (similarly, you can find the states in
about:histograms/Accessibility.ModeFlag). You can enable features via the Accessibility page, or by You can also passing the command line argument
--force-renderer-accessibility into the browser.
In some cases, you may be surprised to find some of the accessibility features enabled even when you have not manually enabled them:
This can happen when the browser detects interactions from a UI Automation tool; such API calls are mostly from accessibility tools like screen-readers. However, some features like Windows 10’s Text Cursor Indicator:
…are implemented using UIA, and when this feature is enabled, the browser enables the corresponding accessibility features.
Back in the spring, some improvements to the Accessibility code caused a series of regressions that would result in crashes, hangs, and memory exhaustion when a loading many pages, including YouTube:
These regressions were impactful for many customers who didn’t expect to be running the impacted code. Fortunately, the problems were quickly fixed.
Unfortunately for end-users, tracking down how Accessibility features got enabled on their browsers
is presently used to be non-trivial. (Update: read on)
For Microsoft Edge users running Windows 10 version 20H1 or later, visiting
about:histograms/UIA will show a truncated hash of the process name of the UIA client:
The value shown is the Integer representation of the first four bytes of the SHA-1 Hash of the process name. Some common values include:
|Truncated Hash||Process Name|
|EoAExperiences.exe (Win10 Text Cursor Indicator feature)|
Unfortunately, there’s no easy way to go from a truncated hash back to the original string; hashes are one-way. (The only way to do it is brute force — start with a list of possible strings and hash them all to find a match).
A simple PowerShell script mostly written by Artem Pronichkin allows you to get the hashes of all of your running processes, which you can then compare to the reported value:
n the future, we hope to streamline this experience somewhat, but for now, it’s an annoyingly geeky scavenger hunt.
Update: In Edge 93+, the
edge://accessibility page includes a simple “Show Client Info” button. Easy peasy.