Markdown Viewer for Firefox: browser Markdown rendering and export
Markdown Viewer by xicilion is a Firefox extension for viewing Markdown files without leaving the browser. It renders .md and .markdown files into styled HTML, offers GFM compatibility, and supports local and remote files for quick previews. The extension includes theme selection, diagram and formula rendering, automatic table of contents, and one-click export to Word. It targets developers, technical writers, and students who need fast, private document previews integrated into a desktop workflow. Settings expose granular renderer choices for display and export.
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What the extension does for documentation browsing
The extension converts raw Markdown into styled HTML inside Firefox, with automatic rendering of .md and .markdown files. It accepts both local (file://) and remote (http/https) sources and supports GitHub Flavored Markdown elements such as tables and task lists. Syntax highlighting covers over 100 programming languages, making the extension suitable for reading README files and code-focused notes without launching a separate editor.
How private your previews remain
Rendering is performed locally within the browser, a design that preserves document data on the device and permits offline use. The extension requires the browser permission to access file URLs for local files, which the user must enable via the add-ons manager. These choices mean the rendering process does not send content to external servers and keeps formula and diagram processing on-device.
How it handles advanced documentation elements
The extension supports complex elements commonly found in technical documents, including math and diagrams. It offers math rendering through KaTeX or MathJax and diagram support for Mermaid, PlantUML, draw.io, Vega and Graphviz. Additional conveniences include automatic table-of-contents generation, more than 29 professional themes such as GitHub Light/Dark and Solarized, and a one-click export to Microsoft Word (.docx) for sharing or archival workflows.
Where it fits across editors and devices
Markdown Viewer exists primarily as a desktop browser extension for Firefox, and the project also provides compatibility on some Chromium-based browsers and an equivalent VS Code extension. That distribution places the extension firmly in desktop documentation workflows and editor-integrated pipelines rather than mobile browsing scenarios. The availability on several desktop platforms makes it easy to slot into an existing developer or writer setup.
Final assessment: a desktop-focused preview tool that suits documentation workflows
Markdown Viewer is a practical option for developers and technical writers who need reliable in-browser document previews and export capabilities. One consideration is its desktop emphasis, which makes it less natural for mobile-first reading. The extension suits anyone who manages local or repository-based Markdown and prefers rendering and export actions performed on their device rather than via external services.
