When something outside Chrome asks for a profile, for example a Dock launcher or a Terminal command, Chrome treats it as a request to open, and the only thing it can do with that is create a window. No flag or script says "raise the window this profile already owns". Getting back needs the operating system to find and raise it.
What is happening
Launch commands such as open -na "Google Chrome" --args --profile-directory="Profile 1" hand Chrome a profile name. Chrome's start-up code opens a browser window for that profile. It does not look for one that is already there.
This is why a Dock shortcut built from Automator seems to "multiply" windows: each click makes another.
What does not fix it
- A different command-line flag: none of Chrome's switches means "focus existing window".
- AppleScript: Chrome can list windows, but nothing in its scripting dictionary says which profile owns a window.
- URL schemes: they open a page, not a profile window.
What does
Getting back to an open window has to be done by macOS itself: locate the profile's window among all Chrome windows and raise it. Casement does this, using each window's title and what it launched. It is why a Casement profile icon takes you back instead of adding another window.
Habits that help meanwhile
- Use the Profiles item in the menu bar to jump to another profile's open window.
- Press ⌘` to cycle through Chrome windows.
- Close the extra windows from the Window menu instead of one at a time.
Why not just script it?
People often try AppleScript to find the right window. Chrome's scripting interface lists windows and their tabs, but it has no property that says which profile a window belongs to. You can guess from titles, and that works until two profiles open the same site. A reliable answer looks at what launched each window as well as its title.
How Casement decides
When Casement opens a profile it remembers which Chrome windows appeared as a result. Later it also reads the title text Chrome adds for non-default profiles, and when a new window appears it assumes it belongs to the profile of the window you were just using. Those three signals together place a window with a profile far more often than any one alone, and where it cannot tell, it prefers doing nothing to raising the wrong window.
Questions people ask
Is this a bug in Chrome?
It is how Chrome handles external requests. A request to open a profile has no "if one exists, use it" mode.
Does Firefox or Edge behave the same way?
Behaviour differs by browser and version. This page describes Chrome.
Try Casement
Casement is a menu-bar app for Mac that puts each Chrome profile in the Dock as its own icon and adds snap layouts, hover-to-focus, a window switcher, Dock window lists, a drop shelf and display controls..