Like all Chromium-based browsers, Opera does not support Java - but I'm sure you really meant javascript (common mistake).

@krishmohanhaha hey o/ well, i thinking here... this topic here in windows section have a same problem to share videos to facebook. My advice is the same... first report it has a bug to Opera Bug Report And them try to use Opera Beta for mac, and say to us if in Opera Beta if has the same bug.

Even stable is quite the a rescource hog - albeit still faster than Chrome/FF/Edge. It's a good thing that they are yet again (Chromium) introducing new RAM weight loss methods.