Markdown is a lightweight markup language which uses plain text to describe formatting information, such as # Heading, 1. numbered list, bold, etc. This add-on identifies markdown documents by the extension in the URL (.md, .markdown, etc.). When you navigate to a markdown document, if the content is plain text, this add-on formats it into HTML (with headings, bold text, etc.) as described in the document and displays it directly in your browser. <strong>Features</strong> <ul> <li>Renders markdown files on the web <em>and</em> local files (<code>file://</code> URLs).</li> <li>Rendering is triggered through a button in the URL bar.<br /> Automatic rendering is available optionally (requires more permissions to check pages for markdown).</li> <li>Works securely, by rendering pages inside a sandboxed iframe.</li> <li>Adjustable rendering style: <ul> <li>Out of the box dark mode support</li> <li>Pick page styling from default or github-lookalike.</li> <li>Pick code coloring from all highlight.js styles</li> <li>Add your own custom CSS (in the addon preferences)</li> </ul> </li> <li>Use a separate extension page to for heavy pages and environments that try to download markdown files, with <ul> <li>Light browser footprint, by rendering pages in a separate worker thread</li> <li>One-time file picker confirmation, to access local files</li> </ul> </li> <li>Prepending <code>ext+view-markdown:</code> to an URL opens that page in the extension for rendering.</li> <li>Supports header anchors (i.e. links).</li> <li>Optional markdown syntax extensions: <ul> <li>checkboxes,</li> <li>footnotes,</li> <li>fancy lists (e.g. roman numerals)</li> <li>laTeX,</li> <li><a href="https://mermaid.js.org/syntax/examples.html">mermaid.js</a> diagrams</li> <li>front matters,</li> <li>and emojis.</li> </ul> </li> <li>Download rendered result as static HTML page</li> <li>Link to page source</li> <li>Respects website security, including <code>Content-Security-Policy</code> headers, by not automatically injecting code into such pages even when automatic rendering is enabled. Rendering can be forced manually through the URL bar button.</li> </ul> ⚠ In order to open local files, check the "Access local files on your computer" permission in the "Permissions and data" tab of the addon's settings ⚠ On Linux and macOS, due to Firefox limitations, your browser may try to download a local markdown file instead of opening it. Simply prepend <code>ext+view-markdown:</code> to the <code>file://</code> URL and confirm the access, or open the markdown viewer page through the toolbar button and select the desired file from a file picker. <strong>Permissions</strong> This add-on requires minimal permissions to do its job. There are: <ul> <li>Storage (<em>mandatory</em>, not shown by Firefox), to store preferences (including your personalized CSS) in your sync profile.</li> <li>Active tab (<em>mandatory</em>, not shown by Firefox), to access a page’s URL and contents for rendering, when the URL bar button is clicked.</li> <li>Host permissions (<em>optional</em>, presented as “access data on all websites”), to check pages whose URLs have markdown file extensions (<code>.md</code>, <code>.markdown</code>, etc.) for renderable markdown.</li> </ul>