Source Code & Font Viewer — HTML/CSS/JS/JSON/XML Firefox

Source Code & Font Viewer — HTML/CSS/JS/JSON/XML

View & format source code with syntax highlighting — HTML, CSS, JS, JSON, XML — plus a font viewer with glyph grid.

Features & Capabilities

Tired of staring at your browser's bland, unstyled source viewer? Source Code & Font Viewer is here to fix that. View — and format — the source of any web page with proper formatting and beautiful syntax highlighting, right from the "View Page Source" context menu or with a single click on the toolbar icon. No more walls of unreadable text. Just clean, colorized code, the way it should be.

✨ What you get: • Beautiful syntax highlighting for HTML, CSS, JavaScript, JSON & XML • Automatic formatting & beautification — pretty-print minified CSS, JS, JSON & HTML • Automatic in-place formatting when you open a raw CSS/JS/JSON/XML file directly • Full-text search (Cmd/Ctrl+F) across the entire source — not just the visible part — with next/previous, match case, whole word, regular expressions, and advanced structural search modes (XPath, CSS Selectors, JSONPath) • One-click download of the formatted source with a smart filename — downloaded HTML still renders locally, and stylesheets keep finding their fonts & images • A built-in font viewer — preview any web font (woff2, woff, ttf, otf) with your own sample text, size, weight & style, plus a glyph grid of the characters it covers (click a glyph to copy it) • A range of light & dark themes • Word wrap, line numbers & code folding • Clickable links to jump between resources without leaving the viewer • One-click switch back to the browser's native source view • Available in multiple languages

Great for developers, web designers, and anyone who needs to view or format HTML, CSS, JavaScript, JSON, or XML source code — or inspect a web font. a clean source code viewer, JSON/XML viewer, font viewer, and code formatter in one.

User Growth & Download Statistics

Manifest V3 Add-on
By:
Nicolas Dos Santos
Daily users:
15 4
Rating:
4.50
(2)
Version:
1.9.0 Last updated: 2026-08-31
Version code:
6452308
Creation date:
2026-05-04
Firefox add-on GUID:
source-viewer@kobee1203.github.io
Firefox add-on numeric ID:
3009010
Weekly download count:
7
Firefox on Android:
No
Risk:
High risk impact High risk likelihood
Permissions:
Host permissions:
  • <all_urls>
  • http://*/*
  • https://*/*
Content scripts matches:
  • *
Size:
687.14KB
URLs:
Website
Full description:
See detailed description
Source:
Firefox Add-ons Store
Data ingested on:
2026-09-07
Compare stats and ranking:

Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.
Developed by:
Nicolas Dos Santos
Firefox Add-ons Store
https://addons.mozilla.org/firefox/addon/source-code-viewer/
Website:
https://github.com/Kobee1203/Kobee1203.github.io/issues

Permission Change History

2026-07-19: Version 1.4.0 → 1.5.0
Add Host permissions: http://*/* https://*/*
Add Permissions: scripting

User Reviews

Maybe you can just take over the context menu ("View Page Source") by mimicking clicks on the extension icon? ps. There's white flash with clicking on the extension icon in dark mode. --------- Hope to reduce the flickering when taking over the browser's native "View Source" page, ideally achieving a seamless takeover. Hope to provide the functionality to adjust the font size.
by 阳熙*****, 2026-08-24

Work fine! With it clean interface (i use the GitHub Dark them) and it search capacity Should be very useful.....
by de*****, 2026-08-23
View all user reviews ›

Is Source Code & Font Viewer — HTML/CSS/JS/JSON/XML Safe?

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.

Source Code & Font Viewer — HTML/CSS/JS/JSON/XML 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.
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  • High ******* ******* **** *** ****** ***** *** ***** ** ******* **** ********* ********* ** * *********** *****
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 Add-ons Store, 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.

Source Code & Font Viewer — HTML/CSS/JS/JSON/XML may not be trust-worthy. Avoid installing if possible unless you really trust this publisher.

Risk likelihood analysis details
  • High This extension was recently updated in the past month. New updates may not be stable or safe.
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  • Medium **** ********* *** ***** ** *** **** * ******* *** ********** *** *** ** ****** ** *****
  • Good **** ********* *** **** **** *******
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