Markdown Viewer

Name: Markdown Viewer
Rating: 3.8472 (72 reviews)
Author: simov

By: simov Add-on

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

Overview

Firefox Add-ons Store

Daily users

16,075 ▲ 491

Data as of 2026-09-06

Rating:

3.85 ▼ 0.04

(72)

Version:

5.2.2

Last updated: 2023-10-30

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

Add-on Developer Tools Open Source

By:

simov

Daily users:

16,075 491

Rating:

3.85

(72) 0.04

Version:

5.2.2 Last updated: 2023-10-30

Version code:

5641909

Creation date:

2017-10-21

Firefox add-on GUID:

markdown-viewer@outofindex.com

Firefox add-on numeric ID:

866049

Weekly download count:

721

Firefox on Android:

Risk:

Permissions:

Host permissions:

file:///*

Size:

1.75MB

Email:

si*****@outofindex.com

URLs:

Website

Full description:

Source:

Firefox Add-ons Store

Data ingested on:

2026-09-06

Compare stats and ranking:

Ranking

# 591 ▲ 2

Other rankings

#81 in Other extensions ▲ 1

#1 in viewer keyword 57

#59 in countdown keyword 15 ▼ 3

#187 in release keyword 24 ▲ 1

#199 in document keyword 37 ▼ 3

Upgrade to see more rankings

Other platforms

Markdown Viewer (v5.3)

500,000 4.28

(419)

Markdown Viewer (v5.3)

152,876 4.30

(43)

For Developers

Monetize with App Pass Boost with Extension Booster

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

doesn't appear to do anything. Cannot follow what the video is telling me to do.

by Fi*****, 2026-09-04

Got it to work for Firefox Windows - eventually. Documentation on git not so good - watch the vimeo vid very carefully at start. It requires "Access your data for all websites". If you you go into the Addons > markdown viewer > manage > permissions: toggle "Access your data for all websites" it will NOT work. This setting will NOT stick. You will navigate, away come back, close firefox, whatevs and it will have reverted to OFF. HOWEVER, if you do as the video does at 00:30-00:40, you will receive the pop-up "Access your data for all websites" it will then work. NB. This is a brand-newey fresh install on windows. not a single other thing installed. It may well be a bug of firefox. I wasted a bit of time working this out. Given it's free, I prefer to give helpful feedback. Doc needs to be a bit more explicit - neither I nor AI picked it up. Thanks for the tool.

by *****, 2026-08-30

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.
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