Markdown is a lightweight markup language created by John Gruber in 2004. It lets you format text using simple, readable syntax that converts to HTML. Markdown is used everywhere: GitHub READMEs and issues, Reddit comments, Notion pages, Discord messages, Stack Overflow answers, and countless documentation sites.
Its simplicity is its strength. You don't need to learn HTML tags or use a visual editor. Just type naturally with a few symbols for formatting, and you get clean, structured output.
| Syntax | Result |
|---|---|
# Heading 1 | Heading level 1 |
## Heading 2 | Heading level 2 |
**bold** | Bold text |
*italic* | Italic text |
~~strikethrough~~ | Strikethrough text |
[text](url) | Hyperlink |
 | Image |
`inline code` | Inline code |
```lang | Fenced code block |
> quote | Blockquote |
- item | Unordered list |
1. item | Ordered list |
- [x] task | Task list checkbox |
--- | Horizontal rule |
GitHub Flavored Markdown is a superset of standard Markdown used on GitHub. It adds several features that have become industry-standard: tables (using pipes and hyphens), task lists (checkboxes with - [x]), strikethrough text (with tildes), fenced code blocks with syntax highlighting, and auto-linked URLs. This previewer supports all GFM features.
|) to separate columns and hyphens (-) for the header row separator. For example: | Header 1 | Header 2 | followed by |----------|----------| and then | Cell 1 | Cell 2 |.```javascript), write your code, then close with three backticks. Common languages include js, python, html, css, json, and bash.