Offline Markdown Preview

Your Markdown, diagrams, and math — rendered locally in your editor.

Read while you write, find your place in long documents, and export the finished preview to HTML or PDF. Mermaid, KaTeX, and syntax highlighting are bundled with the extension. No rendering service, document upload, or telemetry.

Install from Visual Studio Marketplace · Install from Open VSX

Quick start · Supported editors · Features · Demos · Configuration · Privacy · Help

Quick start

Use a compatible desktop editor from the supported editors below. PDF export also needs a local installation of Chrome, Edge, or Chromium.

1. Install Offline Markdown Preview using your editor's registry:

   • VS Code: use the Visual Studio Marketplace listing, or run the command below in a terminal with VS Code's code command.
   • Open VSX-compatible editors, such as VSCodium: search the editor's Extensions view for Offline Markdown Preview by bowlerr, or visit the Open VSX listing.

   # VS Code CLI
   code --install-extension bowlerr.offline-markdown-preview

2. Open a Markdown file. The preview opens automatically when a Markdown editor becomes active.

3. Start writing. The preview updates as you type, and editor and preview scrolling stay in sync.

4. Use Contents to jump between headings, Search to find text, or Export to save HTML or PDF.

Prefer to open the preview yourself? Set offlineMarkdownViewer.preview.autoOpen to false, then run Offline Markdown Preview: Open Preview from the Command Palette. Open Preview in Current Group is available too.

Supported editors

The extension targets desktop editors that support the VS Code 1.90 extension API or newer.

Editor	Installation
VS Code	Install from the Visual Studio Marketplace.
VSCodium	Search its Extensions view, which uses Open VSX by default, or visit the Open VSX listing.
Cursor	Search its Extensions panel, which uses Open VSX, for Offline Markdown Preview by bowlerr.

Automated application tests cover VS Code 1.90 and current stable. VSCodium and Cursor provide compatible extension installation paths; their runtime behavior with this extension has not been independently verified.

Editor missing or extension not working? Report an editor compatibility issue.

Made for reading and writing

Workflow	What you get
Write and review	Live updates, scroll sync, and a preview that keeps your reading position during edits.
Explain an idea	Mermaid diagrams, KaTeX math, and highlighted code blocks, rendered with bundled libraries.
Find your place	A contents list, heading quick pick, copyable heading links, and search across code and inline formatting.
Explore diagrams	Pan and zoom with the mouse, keyboard, or diagram toolbar.
Share your work	HTML and PDF exports from the completed preview, preserving its background and text colors.
Choose your style	Installed GitHub preview styling, your own CSS, and optional frontmatter display.

See it in action

Choose a demo to open the animation.

Demo	Take a look
Live preview and scroll sync	Watch edits and scrolling stay together →
Mermaid and math	Watch diagrams and equations render →
Contents navigation	Watch heading navigation →
Remote image download	Watch an explicit image download and local cache →

Navigate without losing your place

Search includes fenced code and phrases split across inline formatting. Broad queries show the first 1,000 matches and indicate when that limit is reached; refine the query to narrow the results.

With focus inside the preview:

Shortcut	Action
Ctrl+F / Cmd+F	Open or focus search
Enter / Shift+Enter in search	Next / previous match
Escape	Hide search and return focus to its toggle
Arrow keys on a focused diagram	Pan the diagram
Enter / Space on a focused local image	Open the image

The contents list keeps keyboard focus when you select a heading. Diagram controls also support zoom, fit, and actual size; see the full shortcut reference.

Export the finished preview

Use the preview's Export button or run Offline Markdown Preview: Export HTML or Offline Markdown Preview: Export PDF.

• HTML: saves the rendered document and styles. Local images remain file references by default. To include their contents in the HTML file, enable offlineMarkdownViewer.export.embedImages and review the confirmation before exporting.
• PDF: uses a local Chrome, Edge, or Chromium installation. It waits for images and fonts; layout can vary slightly by browser and platform.
• Consistent output: export captures a completed preview. A document change during capture or a preview-rendering timeout cancels the export with a message so you can retry.

Exports block remote images by default and prevent document scripts from running. Enabling remote images also enables them during export. See export settings and limits.

Make it yours

Open your editor's Settings and search for Offline Markdown Preview, or edit your settings JSON. For example:

{
  "offlineMarkdownViewer.preview.autoOpen": false,
  "offlineMarkdownViewer.preview.showFrontmatter": true,
  "offlineMarkdownViewer.preview.customCssPath": ".vscode/markdown-preview.css"
}

Put the CSS path in workspace or folder settings and keep the file inside that workspace. For a stylesheet shared across projects, use offlineMarkdownViewer.preview.globalCustomCssPath in user settings instead.

Run Offline Markdown Preview: Set Custom CSS to choose a stylesheet interactively or reuse the installed Markdown Preview Github Styling extension. Styles apply in this order: base styles → installed GitHub styles → global CSS → workspace CSS, following the normal CSS cascade.

All settings and commands · Custom CSS setup and examples

Offline by default

Rendering uses local, bundled libraries. The extension does not upload your Markdown or collect telemetry. Preview and export do not require a network connection with the default settings.

• Remote images start blocked. Choose Download Image to fetch a specific URL and cache the image locally, or explicitly enable offlineMarkdownViewer.preview.allowRemoteImages to load remote images directly. These actions make network requests.
• HTML sanitization is enabled. A Content Security Policy restricts what the preview can load and run. Disabling sanitization is unsafe for untrusted content.
• External links ask first. Opening a link uses your browser after confirmation by default.
• Local image access stays within allowed roots. Image actions and embedding are limited to the document's workspace, its containing directory outside a workspace, or the extension's image cache. Escaping symlinks are rejected.
• Image downloads have limits. Local images and explicit downloads use the configured size limit, which defaults to 24 MB. Downloads also have a 30-second timeout.

Use Show Remote Image Cache Usage or Clear Remote Image Cache from the Command Palette to manage downloaded files. The cache reference explains storage locations and session behavior.

Need a hand?

If you see…	Try this
A diagram or equation shown as source	Check its syntax and the enableMermaid / enableMath settings.
A missing image	Check the path and size limit. For a remote image, use Download Image or explicitly allow remote images.
CSS that does not apply	Check the file's location, .css extension, and setting scope. Follow the styling guide.
An export cancelled before saving	Wait for the preview to finish rendering, then retry.
A PDF export failure	Check that a supported browser is installed, then open View → Output → Offline Markdown Preview for diagnostics.

See troubleshooting and known limits for more detail. To report a problem, open an issue with your extension version, editor name and version, operating system, and a small example that reproduces it.

Project

Free and open source under the MIT License.

Changelog · Contributing · Credits and bundled libraries · Source on GitHub