Extpose EXTPOSE
Tool

CRX Viewer

Read the source code of any Chrome or Edge extension without installing it. Browse the files, inspect the manifest, and review permissions right in your browser.

Store: auto-detected from the URL

ExtPose's CRX Viewer opens the source code of any published Chrome or Edge extension right in your browser. There is nothing to install and nothing saved to your machine. Paste a store link or extension ID and start reading the files.

What you can see

The viewer fetches the extension's package, unpacks it in the browser, and shows:

  • A full file tree of everything shipped inside the extension
  • manifest.json, including the permissions and host access it requests
  • Background and content scripts, popup pages, and stylesheets
  • Icons, images, and localized message files

Syntax highlighting makes the JavaScript, JSON, HTML, and CSS easy to follow.

How to view an extension's code

  1. Copy the extension's Chrome Web Store or Edge Add-ons URL, or its 32-character ID.
  2. Paste it above. The store is detected automatically from a link, and the Chrome / Edge toggle lets you override it.
  3. Click View code. The file browser opens in a panel, and you click any file to read it.

Why read extension source code

  • Check which permissions an extension uses and whether it loads remote code or sends data to outside servers.
  • See what an extension actually does before installing it on a work machine or recommending it to a team.
  • Learn how popular extensions structure their manifest, background workers, and content scripts.
  • Compare versions over time, or work out how a competing extension is built.

What to look for

  • The permissions and host_permissions in the manifest. Broad host access such as <all_urls> is worth a closer look.
  • Code that fetches and runs remote scripts, which can change an extension's behavior after you install it.
  • Heavily obfuscated or minified code that hides what it actually does.
  • Network requests to domains you do not recognize.

Viewer or download?

The viewer is read-only and runs in your browser, so it is the quickest way to glance at how an extension is built. If you need the files locally (to diff versions, run your own tooling, or load the extension unpacked), use the CRX Downloader instead.

Frequently asked questions

What is a CRX viewer?
A CRX viewer unpacks an extension's package in your browser and lets you read its source files, including the manifest, scripts, pages, and styles, without installing the extension.
Can I see any extension's source code?
You can view any extension that is published on the Chrome Web Store or Edge Add-ons. Paste its store link or 32-character ID to load it.
Do I need to install the extension to view its code?
No. The viewer fetches the published package and opens it in your browser, so nothing is installed and nothing changes on your machine.
Does it work for Microsoft Edge extensions?
Yes. Paste an Edge Add-ons link or switch the store toggle to Edge, and the package is loaded from the Edge servers.
Is the code I see the real published version?
Yes. The viewer reads the exact package the store serves to users, so what you see is the code that actually ships.
Can I check an extension's permissions?
Yes. Open manifest.json in the file tree to see the permissions and host access the extension requests.
Is anything downloaded to my computer?
No. The viewer is read-only and runs in the browser. If you need the files locally, use the CRX Downloader instead.