What Is Markdown? A Plain-Text Formatting Guide

What Is Markdown?

Markdown is a lightweight markup language that lets you format plain text using simple punctuation. You write **bold** and it renders as bold. Created by John Gruber in 2004, Markdown was designed to be readable as-is and convertible to HTML.

Today it is the default writing format on:

• GitHub, GitLab, Bitbucket (READMEs, issues, PRs)
• Stack Overflow (comments and answers)
• Notion, Obsidian, Confluence (documentation)
• Most static site generators (Hugo, Jekyll, Astro, Next.js MDX)
• Reddit and Discord (partial support)

Core Syntax

Headings

# Heading 1
## Heading 2
### Heading 3

Emphasis

**bold**        → bold
*italic*        → italic
~~strikethrough~~ → strikethrough

Lists

- Unordered item
- Another item
  - Nested item

1. First ordered item
2. Second item
3. Third item

Links and Images

[Link text](https://example.com)
![Alt text](image.png)

Code

Inline code uses single backticks: `code`

Fenced code blocks use triple backticks and support language syntax hints:

```js
const x = 42;
console.log(x);
```

Blockquotes

> This is a blockquote.
> It can span multiple lines.

Horizontal Rules

---

Tables (GitHub Flavoured Markdown)

| Column A | Column B |
|----------|----------|
| Cell 1   | Cell 2   |
| Cell 3   | Cell 4   |

Markdown Flavours

The original Markdown spec left many details undefined, leading to multiple implementations:

Flavour	Where used	Extra features
CommonMark	Specification standard	Strict, unambiguous
GFM (GitHub)	GitHub	Tables, task lists, strikethrough
MDX	React/Next.js	JSX components in Markdown
MultiMarkdown	Extended	Footnotes, citations

Markdown to HTML

Every Markdown renderer converts syntax to HTML. For example:

## Hello World

This is **bold** text.

Becomes:

<h2>Hello World</h2>
<p>This is <strong>bold</strong> text.</p>

When Not to Use Markdown

• Documents requiring complex layout (multi-column, precise spacing) — use a word processor or LaTeX.
• Rich data tables with merged cells — use HTML or a spreadsheet.
• Heavily branded content requiring precise typography control.

Use the Markdown to HTML Converter to preview any Markdown and copy the generated HTML.