Chrome
Safari
Edge
Firefox

To open your console on Chrome, you can use either F12 or access it via the GUI menu of Google Chrome. To do this, just click on the 3 dot action button in the top-right corner and go to More Tools > Developer Tools.

The Error Console on Safari is disabled by default. You'll need to perform these extra steps before being able to open it.

Go into Safari's preferences (Safari Menu > Preferences) and select the Advanced Tab. From there you'll check the box labeled "Show Develop menu in menu bar".

Once you've enabled that, you can then access the console by using the shortcut Option+Cmd+C or by clicking Develop > Show JavaScript Console

To open your console on Edge, you can use either Ctrl+Shift+I or access it via the GUI menu of Edge. To do this, just click on the 3 dot action button in the top-right corner and go to More Tools > Developer Tools.

To open your console on Firefox, you can use either Ctrl+Shift+J (Cmd+Shift+J on Mac) or access it via the GUI menu of Firefox. To do this, just click on the 3 line action button in the top-right corner and go to More Tools > Browser Console.
Firefox is slightly unique compared to the other three major browsers in that it opens its console in a new window.