I have just created a very simple chrome extension and it works fine. But when I converted to .crx file and try to open it with chrome, nothing happens. my chrome browser versio
I had a similar issue where I was not able to either install a CRX file into Chrome.
It turns out that since I had my Downloads folder set to a network mapped drive, it would not allow Chrome to install any extensions and would either do nothing (drag and drop on Chrome) or ask me to download the extension (if I clicked a link from the Web Store).
Setting the Downloads folder to a local disk directory instead of a network directory allowed extensions to be installed.
Running: 20.0.1132.57 m
Opening the debug console in Chrome, or even looking at the html source file (after it is loaded in the browser), make sure that all the paths there are valid (i.e. when you follow a link you get to it's content, and not an error). When something is not valid, fix the path (e.g. get rid of the server specific part and make sure you only refer to files that are part of your extension through paths like /js/jquery-123-min.js
).
File format
This tool parses .CRX version 2 format documented by Google. In general, .CRX file format consist of few parts:
Magic header
Version of file format
Public Key information and a package signature
Zipped contents of the extension source code
Magic header is a signature of the file telling that this file is Chrome Extension. Using this header the operating system can determine the actual type of the file (MIME type is application/x-chrome-extension), and how should it be treaten (is it executable? is it a text file?). Then the window system can show beautiful icon to the user.
In .CRX files the magic header has a constant value Cr24 or 0x43723234.
The version is provided by vendor. The version bytes are 0x02000000.
The next part of the file contains the length of the public key information and the length of a digital signature.
All .CRX packages distributed via Chrome WebStore should have public key information and digital signature in order to make possible for browser to check that the package has been transmitted without modifications and that no additions or replacements were made.
After all of the header stuff, typically ending up on 307'th byte, comes the code of extension, stored as zip-archive. So the remainder of the .crx file is the well-known .zip archive.
.crx file opened in the hex editor called HexFiend (on Mac) The header part of a .crx file selected on the picture above. Obviously, you can extract the remaining .zip archive "by hand" using any simple hex editor. In this example, we use handy HexFiend editor on Mac.
The CRX Extractor loads a file provided, checks a magic header, version and trims the file, so only .zip archive remains. Then it returns obtained .zip archive to user.
ref:
https://crxextractor.com/about.html
https://github.com/vladignatyev/crx-extractor
I arrived to this question looking for the same but for Chromium (actually I'm using https://ungoogled-software.github.io). So in case anyone else is looking for the same:
Handling of extension MIME type requests
Always prompt for install
In case Chrome tells you "This can only be added from the Chrome Web Store", you can try the following:
Update: appears to have stopped working since Chrome 80
Drag & Drop the '.crx' file on to the 'Extensions' page
Settings - icon > Tools > Extensions
( the 'hamburger' icon in the top-right corner )Enable Developer Mode ( toggle button in top-right corner )
Drag and drop the '.crx' extension file onto the Extensions page from step 1
( crx file should likely be in your Downloads directory )Install
Source: Chrome YouTube Downloader - install instructions