Extension source viewer

Name: Extension source viewer
Rating: 4.8889 (108 reviews)
Author: Rob W

View source code of Firefox add-ons and Chrome extensions (crx/nex/xpi) from addons.mozilla.org, the Chrome Webstore and elsewhere, with CRX Viewer (crxviewer).

Download

Install Compare

The Extension Source Viewer Chrome extension enables users to effortlessly view and download the source code of Firefox add-ons and Chrome extensions, including those for Opera, Edge, and Thunderbird. When detected, it adds a convenient button next to the address bar providing options to download the extension as a zip file or view its source directly.

The viewer tab offers advanced features such as syntax highlighting, automatic code beautification, regex-based file filtering and content search, image preview, and hash calculations for file integrity. Users can navigate search results easily, explore embedded zip files, and obtain permalinks within extension files. This versatile tool also facilitates downloading Chrome Web Store extensions for different platforms. Known as CRX Viewer or crxviewer, this extension enhances transparency and accessibility for developer and user communities.

Add-on Developer Tools Productivity Programming

By:

Rob W

Daily users:

1,538 -10

Rating:

4.89

(108)

Version:

1.7.0 Last updated: 2023-12-10

Version code:

5663065

Creation date:

2016-07-24

Risk:

Permissions:

tabs
storage
contextMenus
downloads
alarms
cookies
webRequest
webRequestBlocking
*://*/*

Size:

241.70KB

Email:

ro*****@robwu.nl

URLs:

Website

Full description:

Source:

Firefox Browser Add-ons

Updated:

a day ago

Ranking

# 2,374 ▼ 12

Other rankings

#275 in Web Development ▼ 3

#4 in source keyword 29

#9 in source code keyword 26

#10 in resource keyword 34

#18 in viewer keyword 72

Upgrade to see more rankings

Other platforms

Chrome extension source viewer (v1.7.0)

100,000 4.59

(427)

User reviews

The Extension Source Viewer Firefox add-on is highly valued for enabling users to verify add-on source code before installation, enhancing security and transparency. Reviewers praise its practical and user-friendly nature, recommending it as essential for cautious users. However, some report compatibility issues with Waterfox Classic, including missing icons and errors when viewing code directly from Mozilla pages. Additionally, updates sometimes require manual uninstall and reinstall steps. Despite these minor issues, it remains a trusted tool for examining add-ons' origins and ensuring safer installation experiences.

Pros

Allows users to inspect the source code behind Firefox add-ons before installation.
Provides security insight to check for potentially malicious behavior in add-ons.
User-friendly and practical tool praised for its usefulness.
Highly recommended for advanced users who want transparency about add-ons.
Valued as an essential tool to increase user trust and safety in installing add-ons.

Cons

Some compatibility issues with Waterfox Classic, such as missing CRX icon in the address bar.
Occasional errors when attempting to view code directly from Mozilla add-on pages in certain browsers.
Update process may require uninstalling old versions before reinstalling the new one.

Recent reviews

by Ka*****, 2025-05-19

by Dr*****, 2025-04-07

by 远离*****, 2025-03-24

View all user reviews ›

Extension safety

Risk impact

Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

Extension source viewer requires some sensitive permissions that could impact your browser and data security. Exercise caution before installing.

Risk impact analysis details

Critical Grants access to browser tabs, which can be used to track user browsing habits and history, presenting a privacy concern.
Critical ****** ****** ** *** ********* ****** * *********** ******** **** ** ** *** ******* *** ****** **** **** *** ******* *****
High ****** *** ********* ** ******* *** ******* ******* ** ****** *** *** ******** ******
Medium ****** ********** ** ******** ********** *** ********* ******* ******** ****** ******** ****** ********

Risk likelihood

Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Browser Add-ons, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

Extension source viewer has earned a fairly good reputation and likely can be trusted.

Risk likelihood analysis details

High This extension has low user count. Unpopular extensions may not be stable or safe.
Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
Good **** ********* *** **** **** *******

Upgrade to see full risk analysis details

Instantly check and monitor your browser extensions' risks and permissions with Extension Guard.