How do I disable firefox console from grouping duplicate output?

Update [2022-01-24]

Seems like the below option doesn’t work as expected. feel free to report it as a bug

Update [2020-01-28]

Firefox team added option to group similar messages, which is enabled by default.

You can access to this option via Console settings

• Open up Firefox’s dev tools
• Select Console tab
• Click on gear button (placed at the right of the toolbar)
• Change the option as you wish

Original Answer

As I mentioned in comment section, There is no way to achieve this at the moment. maybe you should try to request this feature via Bugzilla@Mozilla

Also you can check Gaps between Firebug and the Firefox DevTools