How to switch account in Minecraft Launcher

Question

I own multiple Minecraft Accounts (now migrated to Microsoft Accounts). I want to choose which one to use when starting Minecraft.

The official Minecraft Launcher appears to have an interface for this, but it does not work. Clicking anything in the switcher menu (Help, Manage profile, Manage Minecraft: Java Edition profile, Log out, or View accounts) simply does nothing but close the drop down menu.

How can I log into multiple accounts and switch between them?

Bug report

Answer 1

Workaround (simple)

First clicking Skins makes the account switcher menu do something useful. Now I can log out and then back in again with a different account.

Actual solution (requires config file editing)

Multiple accounts can actually be logged in at the same time. You just can not log in a second account. The Minecraft Launcher stores information about the logged in account(s) in a file called launcher_accounts.json in the Minecraft folder (see Where is my Minecraft folder on Windows?).

1. Using above Workaround, you can obtain multiple copies of said file with different accounts logged in.

2. Edit the file by copying the entry under accounts from one file and adding it to the other. Make sure to separate them with a comma. Even more than two accounts should work

   {
     "accounts" : {
       "59[…]b" : {             <-- start of first account
         "accessToken" : "",
         […]                    (heavily shortend, actual file has many more rows)
         "username" : "H[…]"
       },                       <-- add the comma
       "e9[…]d" : {             <-- start of second account
         "accessToken" : "",
         […]
         "username" : "U[…]"
       }                        <-- copy up to here
     },
     "activeAccountLocalId" : "59[…]b",
     "mojangClientToken" : ""
   }
   

3. Now you can switch between accounts from the drop down menu. You might need to re-enter you password the first time you switch.