I have a JavaScript code running perfectly in all browsers except Firefox. I am running it in Firefox Quantum Version 66.0.2 (64-bit). I have three HTML input controls, all have their display style set to none. Clicking on a link shows first input. On focusout event of first input, first input hides and second input becomes visible. Similarly on focusout of second input, second input hides and third becomes visible. I wrote simple function for this. They are working in all other browsers. But in firefox when 'Click to show first' is clicked, it shows 'first' input. When tab is pressed then focusout events of 'second' and 'third' are fired by itself and 'second' and 'third' inputs are never shown. Interestingly if input type of all is changed from number to text then same code works fine. Here is the jsFiddle link https://jsfiddle.net/manpreet_cool/znk43j9w/3/ open this link in firefox, you can see it in action. here is the link to question on stack overflow: https://stackoverflow.com/questions/55437541/firefox-fires-focusout-blur-event-automatically-when-input-type-is-number