Copy To Clipboard in Google Chrome Extensions using Javascript. Source: http://www.pakzilla.com/2012/03/20/how-to-copy-to-clipboard-in-chrome-extension/

Copy To Clipboard in Google Chrome Extensions using Javascript

function copyToClipboard( text ){
                var copyDiv = document.createElement('div');
                copyDiv.contentEditable = true;
                document.body.appendChild(copyDiv);
                copyDiv.innerHTML = text;
                copyDiv.unselectable = "off";
                copyDiv.focus();
                document.execCommand('SelectAll');
                document.execCommand("Copy", false, null);
                document.body.removeChild(copyDiv);

Hey, I think I have an even cleaner version of this, which a) uses an input instead of a div, and b) keeps the element invisible on the page:

function copyToClipboard(text) {
  const input = document.createElement('input');
  input.style.position = 'fixed';
  input.style.opacity = 0;
  input.value = text;
  document.body.appendChild(input);
  input.select();
  document.execCommand('Copy');
  document.body.removeChild(input);
};

Thanks, @dannyid . The input.style.position = 'fixed' "fixed" (punny, I know) an issue I had that would cause the browser to scroll.

Only thing I had to change was to use a textarea instead of an input in order to preserve line breaks...

doesn't work.. FF 48

Thanks all!

Does the same technique works for copy image into clipbard?

@dannyid const input = document.createElement('textarea'); It's would be better. The textarea will keep the raw format and the input will lose format.