How to view the source of Chrome extensions


You’ve found a great new Chrome extension. Installing it only takes a click, but if you’re not quite sure what it’s doing, whether it’s safe, you might want to take a look at its source code, first.

Chrome Extension Source Viewer (CSEV) is a free extension which makes it easy to inspect the innards of other Chrome add-ons.

Once installed, CESV displays a “CRX” icon in the address bar whenever it can be used. Just browse the Chrome store, find an extension, click the icon and its source is displayed in a new tab.

The main viewer has two panes. Extension files are listed on the left, and clicking any of these displays its code – nicely formatted and with syntax highlighting — on the right.

Developers can filter these files to explore the code, mark-up, locales and other files, run regular expression searches to find the content they need, or save the source locally as a CRX or ZIP file.

Even if you’re not interested in the low-level technicalities, CESV might still be a handy way to find extension images, view image previews and save local copies.

There are other ways to examine extensions. CRX files are just another ZIP variant, so you can probably already use your archive tool to extract the contents.

Chrome Extension Source Viewer does simplify the process, though, and the bonus features — filtering, formatting, image preview — more than justify the download.