Markdown Viewer Firefox

Markdown Viewer

By: simov
Markdown Viewer with 30+ Themes, Dark Mode, MathJax, Mermaid diagrams, Syntax Highlighted code blocks

Features & Capabilities

Markdown Viewer is a versatile Chrome extension designed for seamless rendering of Markdown files both locally and remotely. It offers over 30 themes including dark mode options, enabling users to customize their viewing experience fully. The extension supports GitHub Flavored Markdown (GFM) and includes advanced features such as MathJax formula rendering, Mermaid diagrams for flowcharts, and syntax-highlighted code blocks to improve readability.

Secure by design, Markdown Viewer allows granular access to remote origins and multiple markdown parsers. Additional features include auto-reload on file changes, table of contents generation, emoji conversion, and remembering scroll position. It supports configurable Markdown file path detection, raw and rendered views, and settings synchronization across devices. As a free and open source tool, it provides robust documentation to help users get the most out of their Markdown viewing experience.

User Growth & Download Statistics

Manifest V3 Add-on Developer Tools Open Source
By:
simov
Daily users:
14,441 318
Rating:
3.90
(68)
Version:
5.2.2 Last updated: 2023-10-30
Version code:
5641909
Creation date:
2017-10-21
Risk:
Very low risk impact Low risk likelihood
Permissions:
Host permissions:
  • file:///*
Size:
1.75MB
Email:
si*****@outofindex.com
URLs:
Website
Full description:
See detailed description
Source:
Firefox Add-ons Store
Data ingested on:
2026-06-14
Compare stats and ranking:

Other platforms

Chrome
Markdown Viewer (v5.3)
400,000 4.31 (401)
Edge
Markdown Viewer (v5.3)
141,856 4.40 (42)

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:
simov
Firefox Add-ons Store
https://addons.mozilla.org/firefox/addon/markdown-viewer-chrome/
Email:
si*****@outofindex.com
Website:
https://github.com/simov/markdown-viewer

Permission Change History

2023-03-14: Version 4.0 → 5.1
Add Host permissions: file:///*
Add Permissions: scripting
Remove Permissions: file:///* webRequest webRequestBlocking
Add Optional permissions: webRequest
Remove Optional permissions: https://*/ http://*/

User Reviews

Reviews show mixed results: Markdown Viewer can render Markdown (including Mermaid) inside Firefox when users follow setup steps and grant the necessary permissions. Many praise the extension and responsive support. But reliability hinges on configuration; several reviews report it doesn't work out-of-the-box and requires broad site permissions, local-file access tweaks, or about:config changes. Some environments (notably Linux/Ubuntu) encounter failures, and the extension sometimes fails to register the .md extension. When configured properly, it is valuable; otherwise it can be frustrating.
Pros
  • Renders Markdown in-browser after proper configuration (permissions and settings may be required)
  • Mermaid diagrams render when using the Markdown Viewer
  • Positive user sentiment and gratitude when it works
  • Helpful setup guidance and support for tricky Linux/Ubuntu configurations
Cons
  • Does not work out-of-the-box; requires enabling broad site permissions and configuration steps
  • Local file access is blocked or unreliable due to Firefox security policies
  • Platform-specific issues and packaging quirks (e.g., Ubuntu snap, Ubuntu 22) can cause failures
  • Does not register the .md file extension properly, causing 'open with' dialogs instead of in-browser rendering
Recent reviews
by Fi*****, 2026-05-18

by La*****, 2026-05-07

by Fi*****, 2026-03-31
View all user reviews ›

Is Markdown Viewer 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.

Markdown Viewer does not require any sensitive permissions.

Risk impact analysis details
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.

Markdown Viewer has earned a fairly good reputation and likely can be trusted.

Risk likelihood analysis details
  • Medium This extension has medium user count. Unpopular extensions may not be stable or safe.
  • Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
  • Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
  • Good **** ********* *** **** **** *******
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