What is javascript console and how can you open it to indifferent browsers?

The answer to your question - What is javascript console and how can you open to indifferent browsers is -

Chrome

Opening the “Console” panel of Chrome’s DevTools:

Windows and Linux: Ctrl + Shift + J

Mac OS: Cmd + Opt + J

Note: In addition to the “Console” panel, there also exists a smaller slide-up console which can be toggled via Esc while any of the other panels is active.

Firefox

Opening the “Console” panel in Firefox’s Developer Tools:

Windows: Ctrl + Shift + K

Mac OS: Cmd + Opt + K

Note: In addition to the “Console” panel, there also exists a smaller slide-up console which can be toggled via Esc while any of the other panels is active.

Internet Explorer

Opening the “Console” panel in Internet Explorer’s F12 Developer Tools:

F12, then click on the “Console” tab

Note: In addition to the “Console” panel, there also exists a smaller slide-up console which can be toggled via Ctrl + ` while any of the other panels is active.

Safari

Note: In order to view the console in Safari, you have to enable the “Show Develop menu in menu bar” setting in the “Advanced” pane of Safari’s preferences.

Opening the “Console” panel in Safari’s Web Inspector:

Cmd + Opt + C

Note: In addition to the “Console” panel, there also exists a smaller slide-up console which can be toggled via Esc while any of the other panels is active.

Opera

Windows and Linux: Ctrl + Shift + I

Mac : ⌘+⌥+I