Merging windows of Google Chrome

This functionality now exists in Chrome and has since version 24 or earlier. - So no need for extensions (any more)

Left-click the first tab in the window you want to merge, then hold the shift key and left-click the right most tab. All of the selected tabs for the current window can now be dragged and dropped as as group on another Chrome window.

The Windows To Tabs extension for Chrome will do the trick.

You simply hit a button in Chrome and all tabs from any open windows are merged into one window.

In fact, there are loads of extensions out there, like JoinTabs which gives you more control over what windows are merged into what other windows.

I got confused by the steps provided, re-posting :

1. Left click first tab
2. Hold shift key or ctrl key
3. Left click and hold on another tab, move tab(s) to another window

Version 61.0.3163.100 (Official Build) (64-bit)