It's about the content which is made by the website . The website behaves differently on different browsers.

Saying this I don't mean that the caps lock notification is not available in Firefox .What I mean't is maybe the site has been coded keeping Google chrome in mind .

Report if this reply helped .Thanks!

But in Google Chrome, any space that you can write in, it will show the caps lock notification, Google made this feature in their browser actually, and websites developers don't have to code this or something, it's simple, in any text space, nothing else.

I didn't see this feature in Firefox in any text space :(

Hi,

If you want to leave feedback for Firefox developers, you can go to the Firefox Help menu and select Submit Feedback... or use this link. (You'll need to be on the latest version of Firefox to submit feedback). Your feedback gets collected at http://input.mozilla.org/, where a team of people read it and gather data about the most common issues.

Report back if it helps! Thanks!

I did that, thank you!