CRX File Documentation

Overview

Feature Value
Format name Chrome Extension (CRX)
File Extension .crx
MIME Type application/x-chrome-extension
Developed by Google
Format type Binary
Primary use Distribution of Google Chrome extensions and themes
Zip-based Yes, packaged and compressed as a zip file
Security Includes digital signatures for authentication
Archive structure Contains manifest file (manifest.json), HTML files, JavaScript files, images, and optional locale files
Manifest file Mandatory (manifest.json) contains metadata and settings
Background scripts Defined in manifest.json, used for background tasks
Content scripts Defined in manifest.json, interact with web pages' DOM
Permissions Specified in manifest.json, control what resources or APIs the extension can access
Update mechanism Can specify an update URL in manifest.json for automatic updates
Icons Should provide multiple sizes for different contexts, specified in manifest.json
Browser compatibility Primarily for Google Chrome, but with certain modifications can be made compatible with other browsers supporting WebExtensions API
Popup UI Optional, defined in manifest.json, shown when the user clicks the extension's icon in the Chrome toolbar
Options page Optional, provides a UI for users to change extension settings
Content Security Policy (CSP) Can be defined in manifest.json to add an additional layer of security
Installation Can be installed through the Chrome Web Store or by dragging the CRX file into Chrome