Markdown Editor & Preview — Write Markdown, See HTML Live

The Formula

Markdown is a lightweight markup language created by John Gruber in 2004 that allows you to write formatted text using a plain-text syntax. It converts to structurally valid HTML and is widely used for documentation, readme files, forums, and static site generators.

Variable Definitions

How to Use This Calculator

1. 1

   Type or paste markdown text into the input field. The preview will update automatically.

2. 2

   Use markdown syntax: # heading, **bold**, *italic*, [link](url), `code`, - list item.

3. 3

   Switch between "Preview" and "HTML Source" output formats using the dropdown.

4. 4

   In Preview mode, see the rendered HTML. In HTML Source mode, view the raw HTML output.

5. 5

   Copy the generated HTML or use the live preview to check your formatting.

Quick Reference

Common Applications

• Writing README files for GitHub, GitLab, and Bitbucket repositories
• Creating documentation for software projects and API references
• Writing forum posts and comments on platforms like Reddit and Stack Overflow
• Authoring content for static site generators like Jekyll, Hugo, and Next.js
• Formatting text in note-taking apps like Obsidian, Notion, and Bear

Markdown source (left) is parsed into rendered HTML (right) through the markdown processor

Understanding the Concept

Markdown is a lightweight markup language with plain-text formatting syntax, created by John Gruber in 2004 with significant contributions from Aaron Swartz. The primary design goal was to make it possible to write formatted text using a simple, readable syntax that could be converted to HTML without requiring the user to know HTML tags. Markdown has since become one of the most widely used markup languages in the world, particularly in the software development community. It is the default formatting language on platforms like GitHub, GitLab, Stack Overflow, Reddit, and many others. The philosophy behind Markdown is that the raw text should be readable and publishable as-is, without looking like it has been marked up with formatting instructions. This means that Markdown syntax is intentionally minimal compared to HTML or other markup languages. For example, a heading is indicated by hash symbols (#) rather than angle-bracket tags. While the original Markdown specification by Gruber defined the core syntax, several extensions have emerged over time to add features like tables, footnotes, task lists, strikethrough text, and automatic URL linking. The most notable of these is CommonMark, a standardized specification that resolves ambiguities in the original Markdown. GitHub Flavored Markdown (GFM) builds on CommonMark and adds features specific to GitHub's platform, such as task lists, emoji shortcuts, and table alignment. Markdown is supported by virtually every static site generator, content management system, and documentation tool in use today, making it an essential skill for developers, technical writers, and content creators.

Frequently Asked Questions

Sources & References