What is Markdown Preview?
Markdown is a lightweight markup language that lets you write formatted content using simple plain text syntax. Headers are marked with hash symbols, bold text with double asterisks, and links with square brackets followed by parentheses. This Markdown previewer renders your text in real time, showing you exactly how it will look when published. It supports GitHub Flavored Markdown (GFM) including tables, fenced code blocks, task lists, strikethrough text, and autolinked URLs. All HTML output is sanitized with DOMPurify to prevent cross-site scripting.
How to Use This Tool
Type or paste your Markdown content into the editor on the left side. The rendered HTML preview appears instantly on the right side as you type. You can copy either the raw Markdown source or the generated HTML output using the copy buttons at the top of each panel. The editor starts with sample content demonstrating common Markdown features like headings, bold text, lists, code blocks, blockquotes, and tables. Edit the sample or clear it to start writing from scratch.
Common Use Cases
- Drafting and previewing README files for GitHub, GitLab, or Bitbucket repositories
- Writing technical documentation, API guides, and changelog entries
- Composing blog posts and articles for platforms that accept Markdown input
- Previewing formatted messages before posting to Slack, Discord, or other Markdown-enabled platforms
Why Use a Client-Side Markdown Previewer?
Documentation and technical writing often contain proprietary information, internal architecture details, or unreleased feature descriptions. This previewer runs entirely in your browser with no server communication. Your Markdown content stays on your device throughout the entire editing process. There are no accounts to create, no files uploaded, and no content stored anywhere. This makes it suitable for previewing sensitive internal documentation, client deliverables, and confidential technical specifications.
Frequently Asked Questions
What Markdown features are supported?
This previewer supports the full GitHub Flavored Markdown (GFM) specification. That includes headings (h1 through h6), bold, italic, and strikethrough text, ordered and unordered lists, task lists with checkboxes, fenced code blocks with syntax highlighting hints, blockquotes, horizontal rules, links, images, and tables with alignment. Inline HTML is also rendered but sanitized to remove potentially dangerous elements like script tags.
Is the HTML output safe to use directly in a web page?
Yes. All generated HTML passes through DOMPurify, a well-tested sanitization library that removes any potentially dangerous content such as script tags, event handlers, and data URIs that could execute code. The sanitized output is safe for embedding in web pages, emails, or any context where you need rendered Markdown content without XSS risks.
Can I use this for GitHub README files?
Yes. This previewer uses the same GitHub Flavored Markdown specification that GitHub uses for README files, issues, pull requests, and comments. While minor rendering differences may exist due to GitHub's custom CSS styling, the Markdown syntax interpretation is the same. It is an excellent way to draft and preview your README content before committing it to your repository.