Checking memory usage of chrome extensions
The chrome extensions and firefox addons have been a blessing for users who would like specific functionality added to their browsers which would not be useful for the general public. Developers are able to create extensions for any functionality for their users and have it host and distributed via the chrome web store for free. The only side effect of this is that often developers create extensions with not so well written code that bring about memory leaks in the browser or that simply are memory hogs. This slows down the user's browser and browsing experience and without knowing which extension is the culprit the user will most likely blame the browser developers.
Thankfully, chrome has an tool to see the memory usage of each extension built into the browser itself. You simply need to click on the menu icon and then go to Tools -> Task Manager. As you can see below Lastpass a free password manager has a chrome extension that is using 63MB of memory, while Keywords Everywhere, a google keyword planner tool is using 14MB of memory.
Just because an extension is using a lot of memory does not mean it is necessarily badly written. If the extension provides a lot of value, it may need to use that much memory. However, using this simply tool, you can decide for yourself which extensions to disable, and which to keep. You could also look for alternative extensions which might give the same value, but might use very little memory and cpu.