How do I directly modify a Google Chrome Extension File? (.CRX)

Question

I\'m not sure in which languages those extensions are, I think the are written in Html, Javascript or JSON. As far as I know they are \"compressed\" in a .CRX file.

Answer 1

It's possible to modify the code of .CRX extension, because it's a simple .zip archive. You can download extension, extract it's source code, modify it (test and debug it as it's on your side), and package back into .CRX file.

I googled out this tool to simply download .CRX extension and extract the source code and it worked for me: http://crxextractor.com

Everything it does is parses .CRX file format and extracts actual .zip containing the source code.