Free Markdown Previewer
Write or paste Markdown and instantly see it rendered as HTML with a live preview. Powered by marked, the most widely used open-source Markdown parser for JavaScript with millions of weekly npm downloads. Supports full GitHub Flavored Markdown (GFM) — tables, task lists, strikethrough, fenced code blocks, autolinks, and blockquotes — on top of the CommonMark specification. Switch between four layout modes: side-by-side, stacked, editor-only, and preview-only, plus fullscreen mode for distraction-free writing. All processing happens locally in your browser — no signup, no server, no data sent anywhere.
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What Is Markdown and Why Use a Live Previewer?
Markdown is a lightweight markup language created by John Gruber in 2004 that allows you to format plain text using intuitive symbols — asterisks for bold and italic, hashes for headings, dashes for lists, and brackets for links and images. It has become the universal standard for writing technical content, adopted by GitHub for README files and documentation, by platforms like Notion, Obsidian, and Confluence for notes and wikis, by static site generators like Hugo, Jekyll, and Gatsby for blog posts, and by communication tools like Slack, Discord, and Jira for message formatting. Markdown files are plain text, making them version-controllable with Git, portable across every operating system, and readable even without rendering.
The challenge with Markdown is that you write in plain text but need to see how it renders — especially for complex structures like tables, nested lists, code blocks, and image layouts. A live Markdown previewer eliminates the guess-and-check cycle of writing, committing, and refreshing. This tool shows you the rendered HTML output instantly as you type, so you can catch broken links, misaligned tables, incorrect heading levels, and formatting errors before they reach your audience. The side-by-side layout mirrors the workflow used by professional documentation teams and technical writers worldwide.
This previewer is powered by marked, the most widely used open-source Markdown parser for JavaScript, with millions of weekly downloads on npm. marked is designed as a high-speed, low-level compiler that parses Markdown without caching or blocking, making it ideal for real-time preview applications. It supports the CommonMark specification as the baseline and GitHub Flavored Markdown extensions on top, ensuring your Markdown renders consistently with how it will appear on GitHub, GitLab, Bitbucket, and most modern platforms.
GitHub Flavored Markdown Features Supported
GitHub Flavored Markdown (GFM) is a strict superset of the CommonMark specification, developed by GitHub to extend standard Markdown with features commonly needed in software development workflows. GFM adds tables with column alignment using colons in the separator row, task lists with checkbox syntax for tracking to-dos in issues and pull requests, strikethrough text using double tildes, fenced code blocks with language identifiers for syntax-aware formatting, autolinked URLs and email addresses that become clickable without explicit link syntax, and restrictions on raw HTML for security on multi-user platforms.
This tool has GFM enabled by default, meaning every GFM feature renders correctly in the preview. You can write pipe-delimited tables and see them formatted with proper borders and alignment. Task lists render with checkboxes. Fenced code blocks display with monospace fonts and a distinct background, tagged with the specified language class for optional syntax highlighting. Autolinked URLs become clickable in the preview. If you are writing README.md files, GitHub Issues, Pull Request descriptions, or wiki pages, this previewer shows you exactly what your audience will see.
Beyond GFM, the tool supports all standard Markdown elements defined by CommonMark: ATX and Setext headings (levels 1-6), ordered and unordered lists with nesting, inline code with backticks, block-level code blocks, blockquotes with nesting, horizontal rules, emphasis and strong emphasis, links (inline, reference, and autolink), images with alt text, and hard and soft line breaks. This covers virtually every Markdown construct you will encounter in real-world documentation, blog posts, and technical writing.
Practical Use Cases for Markdown Editing
Developers use this tool most often to preview GitHub README files before committing. A well-formatted README is the first impression of any open-source project — broken tables, misaligned badges, or incorrect heading hierarchy make a project look unprofessional. By previewing locally, you can iterate on formatting instantly without polluting your commit history with typo fixes. The same workflow applies to CONTRIBUTING.md, CHANGELOG.md, LICENSE files, and GitHub Wiki pages that all use Markdown.
Technical writers and content creators use live Markdown previewers to draft blog posts, documentation, API guides, and tutorials. Platforms like Hugo, Jekyll, Gatsby, Next.js, and Docusaurus all use Markdown as their content source. Writing in this previewer lets you verify formatting, test code block rendering, and check link syntax before copying the content into your project. The HTML export feature is also useful for pasting formatted content directly into email newsletters, CMS platforms like WordPress or Ghost, or any system that accepts HTML input.
Students, researchers, and knowledge workers use Markdown for note-taking in tools like Obsidian, Notion, Logseq, and Joplin. This previewer serves as a quick sandbox to test Markdown syntax, learn new formatting tricks, or convert notes to HTML for sharing. The four layout modes — side-by-side, stacked, editor-only, and preview-only — adapt to different screen sizes and workflows, from wide desktop monitors to narrower laptop screens. Fullscreen mode removes all distractions for focused writing sessions.
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How It Works
Type or paste Markdown into the editor on the left.
See the rendered HTML preview update live on the right — switch between side-by-side, stacked, editor-only, or preview-only layouts.
Copy the rendered HTML or the raw Markdown with one click.
Key Features
Privacy & Trust
Use Cases
Frequently Asked Questions
Is this Markdown previewer completely free?
Yes, it is 100% free with no limits, no signup, and no feature restrictions. Some Markdown editors like Typora charge a one-time license fee, while cloud-based editors may restrict features behind paid tiers. This tool gives you full live rendering, GitHub Flavored Markdown support, four layout modes, fullscreen editing, and HTML export at zero cost because all processing runs locally in your browser with no server involvement.
Is my text sent to a server or stored anywhere?
No. All Markdown parsing and HTML rendering happens entirely inside your browser using the marked library. Your text never leaves your device — there are no API calls, no cloud storage, and no analytics on your content. This makes it safe for previewing private documentation, internal READMEs, confidential notes, draft blog posts, or any Markdown you want to keep off third-party servers. You can verify this by checking the Network tab in your browser DevTools while typing.
What is Markdown and why should I use it?
Markdown is a lightweight markup language created by John Gruber in 2004 that lets you format plain text using simple symbols — asterisks for bold, hashes for headings, dashes for lists, and brackets for links. It is the standard writing format across the software industry, used for GitHub READMEs, technical documentation, blogs, wikis, and note-taking apps like Notion and Obsidian. Markdown files are plain text, so they are version-controllable with Git, portable across any platform, and readable even without rendering. Learning Markdown takes minutes and saves hours compared to fighting with rich text editors.
What is GitHub Flavored Markdown (GFM) and how does it differ from standard Markdown?
GitHub Flavored Markdown (GFM) is a strict superset of the CommonMark specification, adding extensions that GitHub developed for use across their platform. GFM adds tables with column alignment, task lists with checkboxes, strikethrough text using double tildes, fenced code blocks with language identifiers, autolinked URLs and email addresses, and disallowed raw HTML tags for security. Standard Markdown (CommonMark) does not include these features. This previewer has GFM enabled by default, so everything you write will render the same way it appears on GitHub, GitLab, and most modern Markdown platforms.
What is CommonMark and how does it relate to GFM?
CommonMark is a formal, unambiguous specification for Markdown syntax, created to resolve the inconsistencies in John Gruber's original Markdown description. It defines exactly how every edge case should be parsed — nested lists, inline HTML, link references, and more. GitHub Flavored Markdown is built on top of CommonMark as a strict superset, meaning every valid CommonMark document renders identically in GFM, but GFM adds extensions like tables, task lists, and strikethrough. The marked library used by this tool supports both CommonMark baseline syntax and the GFM extensions.
What is marked and how reliable is it?
marked is the most popular open-source Markdown parser for JavaScript, with millions of weekly downloads on npm. It has been in active development since 2011 and is used by thousands of websites, documentation platforms, CMS systems, and developer tools in production. marked is designed as a low-level, high-speed compiler that parses Markdown without caching or blocking, making it ideal for live preview applications. It supports GFM extensions including tables, task lists, and strikethrough, and is continuously updated to improve CommonMark specification compliance.
Does this support tables, code blocks, and task lists?
Yes, all three are fully supported through GitHub Flavored Markdown. Tables render with pipe-delimited columns and optional alignment using colons in the separator row. Fenced code blocks use triple backticks with an optional language identifier (e.g., ```python or ```sql) for proper formatting. Task lists use dash-bracket syntax (- [ ] for unchecked, - [x] for checked) and render as interactive-looking checkboxes in the preview. You can also use blockquotes, nested lists, horizontal rules, inline code, images, and links — the full Markdown feature set.
Does this previewer support images in Markdown?
Yes. Standard Markdown image syntax —  — renders images in the preview panel. You can reference any publicly accessible image URL, and it will display inline in the rendered output. This is useful for previewing README files that include badges, screenshots, diagrams, or logos before pushing to GitHub. Note that the images must be hosted at an accessible URL; the tool does not provide image upload or local file embedding.
Can I copy or export the rendered HTML?
Yes. You can copy both the raw Markdown source and the rendered HTML output with one click. The HTML output is clean and ready to paste into email clients that support HTML (Gmail, Outlook), CMS platforms like WordPress or Ghost, website builders, or any system that accepts HTML input. This is a quick way to convert a Markdown document into formatted HTML without setting up a build pipeline, static site generator, or command-line tool like Pandoc.
How does this compare to Typora, StackEdit, and Dillinger?
Typora is a paid desktop application ($14.99 license) that renders Markdown inline without a split view — great for writing but requires installation and purchase. StackEdit is a web-based editor with Google Drive and Dropbox sync, but requires account connections for cloud features. Dillinger is a clean online editor that supports file export to HTML and PDF. This tool is the fastest option for quick Markdown previewing — no installation, no account, no login. It runs entirely in your browser, supports four layout modes including fullscreen, and keeps your text completely private. For quick preview-and-copy workflows, it is harder to beat.
Is the rendered HTML safe from XSS attacks?
The tool renders your own Markdown input locally in your browser — the same security model used by VS Code, StackEdit, and every other Markdown editor. Since you are both the author and the viewer of the content, and no text is shared with other users or stored on a server, there is no cross-site scripting vector. The marked library does not sanitize output by default, so raw HTML in your Markdown will render as-is in the preview. If you plan to use the exported HTML in a multi-user context (like a CMS), you should run it through a sanitizer like DOMPurify before serving it to other users.
Does this previewer support syntax highlighting in code blocks?
Fenced code blocks are rendered with proper formatting and a monospace font. Specifying a language after the opening triple backticks (e.g., ```javascript or ```python) enables the parser to tag the code with the appropriate CSS class. This tool provides clean code block styling with a distinct background. For full IDE-style syntax highlighting with language-specific coloring of keywords, strings, and comments, you would typically integrate a library like Prism.js or highlight.js in your own project. The exported HTML includes the language class attribute so you can apply any syntax theme.
What layout modes are available?
The tool offers four layout modes to match different workflows. Side-by-side mode places the editor and preview next to each other — ideal for wide screens and the classic Markdown editing experience. Stacked mode puts the editor on top and preview below — useful on narrower screens or when you want more vertical space. Editor-only mode hides the preview for focused writing, and preview-only mode hides the editor for reviewing the rendered output. You can also toggle fullscreen mode to expand the entire tool to fill your screen, removing all surrounding page elements for distraction-free work.
Can I use this to preview GitHub README files?
Yes, this is one of the most common use cases. Paste your README.md content into the editor and see exactly how it will render on GitHub. The tool uses GFM-compatible rendering, so tables, badges, code blocks, task lists, images, and links all display correctly. This is much faster than committing, pushing, and checking the GitHub web preview — especially when you are iterating on formatting, fixing broken links, or adjusting table layouts. Many developers keep this tool open in a browser tab alongside their code editor.
What is the maximum document size this tool can handle?
There is no hard character or word limit. The marked library is designed for speed and can parse large documents efficiently. In practice, documents up to 50,000-100,000 words render smoothly on modern hardware. Extremely large files (500+ pages of Markdown) may cause the live preview to lag slightly on older devices because the entire document is re-parsed on every keystroke. For very large documents, you can switch to editor-only mode while writing and toggle to preview-only mode periodically to check rendering.
Does this tool work offline?
Yes. Once the page has loaded and the marked library is cached, all Markdown rendering happens locally in your browser with no network requests. You can type, edit, switch layouts, and preview Markdown without an internet connection. This is useful for writing on planes, in cafes with spotty Wi-Fi, or any situation where you want a reliable, distraction-free Markdown editing environment that does not depend on cloud connectivity.
Limitations
- Does not support custom Markdown extensions beyond GFM
- HTML sanitization may strip some advanced inline HTML
- Very large documents may slow the live preview on older devices
- No built-in file save — copy your work before closing the tab
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