Markdown Preview

Write and preview Markdown with GitHub Flavored Markdown support.

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About Markdown Preview & Technical Guide

Quick Start Guide

Simply paste your Markdown text into the left editor. The right side will instantly render the formatted HTML. You can toggle **GitHub Flavored Markdown (GFM)** for support with tables, task lists, and auto-links. Once finished, use the copy buttons to grab the raw Markdown or the generated HTML for your blog or GitHub documentation.

Technical Background: Secure Rendering

The transition from raw Markdown to styled HTML involves two critical libraries:Marked for parsing and DOMPurify for sanitization.

  • Marked: A high-speed, light-weight Markdown compiler that allows for GFM compliance.
  • DOMPurify: A security-critical layer that scrubs the output to preventCross-Site Scripting (XSS) attacks. Even if malicious script tags are injected via Markdown, they are neutralized before rendering.

Privacy & Security Rationale

Many online Markdown previews transmit your data to a server for processing. Our tool operates entirely client-side. This means your sensitive internal documentation, private proposals, or draft blog posts never leave your computer. We utilize the browser's own memory for rendering, ensuring absolute confidentiality.

Technical FAQ

FeatureDescriptionSupported
GFM TablesStandard pipe-delimited tables✅ Yes
Task Lists- [x] Checkboxes✅ Yes
Inline HTMLRaw HTML tags⚠️ Sanitized
Mermaid DiagramsFlowcharts, sequence diagrams, etc.✅ Yes
Math / LaTeXMathematical symbols❌ Planned

Mastering Basic Syntax

  • # Headers: Used for titles (H1 through H6).
  • **Bold** and *Italic*: Text emphasis.
  • [Link](url): Hyperlinks.
  • ![Alt](img_url): Embed images.
  • - List: Bulleted points.
  • 1. List: Numbered steps.
  • `code`: Inline code snippets.
  • > Quote: Blockquotes.

GitHub Flavored Markdown (GFM)

GFM is an extension of the original Markdown specification that adds support for features essential to developers, such as Tables, Task Lists, and Strikethrough. Our previewer supports these extensions, ensuring that what you see here matches how your README will look on GitHub.

Security and Sanitization

Rendering Markdown into HTML can introduce XSS (Cross-Site Scripting) vulnerabilities if not handled correctly. Our Markdown Preview tool uses DOMPurify to sanitize the output, ensuring that even if you paste untrusted text, your browser remains secure.

🔒 Privacy Commitment

Like all tools in the Dev Tool Kit, this Markdown Preview operates 100% client-side. Your data is processed locally in your browser and is never sent to our servers. Privacy is not just a feature; it's our core architecture.