Following up on a previous question, I have a WebGL application that suffers serious performance issues under Chrome v127 until I set a flag to switch the backend WebGL renderer from Metal/ANGLE to OpenGL. I have a workaround on that browser to direct users to adjust that flag setting and reload the browser, which may be workable for now.

I am also finding similar performance bugs with Safari 17.6 (macOS 14.6.1). If it is possible, I would like to be able to direct users to make a similar adjustment with that browser, if they choose to use it, so that performance can be restored. (Or if it is not possible, direct users to Firefox, which uses OpenGL ES.)

On the desktop version of Safari, I did not see an option in Safari’s Feature Flags to adjust the backend WebGL engine in a similar fashion as can be done in Chrome.

Question: Is there any command-line flag or other approach that can be used to modify Safari’s underlying WebGL rendering engine?

Follow-up question: Similarly, I find problems with performance on current versions of mobile Safari (e.g., iOS 18), and I would like to know what can be done to adjust the backend engine there, as well, if possible.