What is the maximum allowable time between two keystrokes in progressive keyboard shortcuts?

Question

A lot of modern web applications (like Atlassian) have progressive keyboard shortcuts instead of modifier ones, where in two keys are pressed in progression to invoke the action unlike modifier hotkeys where all the concerned keys are to be pressed together.

I am working on defining keyboard shortcuts for a B2B web app, where a lot of users are accustomed to using legacy modifier shortcuts. The idea for introducing progressive keyboard shortcuts is to avoid collisions with browser and system hotkeys, and to make it more scalable and future-proof. However I am concerned that the users would not be able to adapt to progression hotkeys quickly, as their execution pattern is different from pressing keys together, and they might get confused about what is the ideal time lag to press the second key after first.

Answer 1

In the past, a time window of 100-500 milliseconds was required between keystrokes for them to be recognized as a shortcut. However, very few people pressed keys simultaneously, and nowadays, it is possible to use a combination of keys with a longer delay between them.

To test this, I pressed the Command key on my Mac, counted to 10, and then pressed the A key. It successfully selected this window's text since it's the focused element. Therefore, I believe that key combination is more important than timing.

I could not find any documentation for keystroke time, I assume it's because it is not a crucial factor, as mentioned above.

However, if you require more information on keyboard UI, including shortcuts, please refer to the following link: https://learn.microsoft.com/en-us/previous-versions/windows/desktop/dnacc/guidelines-for-keyboard-user-interface-design#creating-shortcut-keys-and-access-keys.