A quick reference for Markdown syntax. Covers headings, emphasis, links, images, lists, code, tables, blockquotes, and extended syntax.
Headings
| Syntax | Result |
|---|---|
| # Heading 1 | Top-level heading (H1) |
| ## Heading 2 | Section heading (H2) |
| ### Heading 3 | Subsection heading (H3) |
| #### Heading 4 | Sub-subsection heading (H4) |
| ##### Heading 5 | Minor heading (H5) |
| ###### Heading 6 | Smallest heading (H6) |
Emphasis & Formatting
| Syntax | Result |
|---|---|
| *italic* or _italic_ | Italic text |
| **bold** or __bold__ | Bold text |
| ***bold italic*** | Bold and italic text |
| ~~strikethrough~~ | Strikethrough text |
| `inline code` | Inline code |
| ==highlighted== | Highlighted text (some parsers) |
| H~2~O | Subscript (some parsers) |
| X^2^ | Superscript (some parsers) |
Links & Images
| Syntax | Description |
|---|---|
| [text](url) | Inline link |
| [text](url "title") | Link with hover title |
| [text][ref] | Reference-style link |
| [ref]: url | Reference link definition |
|  | Inline image |
|  | Image with title |
| <https://example.com> | Auto-linked URL |
| <user@example.com> | Auto-linked email |
Lists
| Syntax | Description |
|---|---|
| - item | Unordered list (also * or +) |
| 1. item | Ordered list |
| - nested | Nested list (indent 2 spaces) |
| - [x] done | Checked task list item |
| - [ ] todo | Unchecked task list item |
| 1. First\n 1. Sub-item | Nested ordered list |
Code Blocks
| Syntax | Description |
|---|---|
| `code` | Inline code span |
| ```\ncode\n``` | Fenced code block |
| ```js\ncode\n``` | Code block with syntax highlighting |
| indented code | Indented code block (4 spaces) |
| ```diff\n+added\n-removed\n``` | Diff syntax highlighting |
| ```json\n{"key": "value"}\n``` | JSON code block |
Tables
| Syntax | Description |
|---|---|
| | H1 | H2 | | Table header row |
| | --- | --- | | Separator row (required) |
| | cell | cell | | Table data row |
| | :--- | | Left-aligned column |
| | :---: | | Center-aligned column |
| | ---: | | Right-aligned column |
Blockquotes & Rules
| Syntax | Description |
|---|---|
| > quote | Blockquote |
| > line1\n> line2 | Multi-line blockquote |
| >> nested | Nested blockquote |
| --- | Horizontal rule (also *** or ___) |
| \ | Escape special characters |
Extended Syntax
| Syntax | Description |
|---|---|
| [^1] | Footnote reference |
| [^1]: Text | Footnote definition |
| term\n: definition | Definition list (some parsers) |
| :emoji_name: | Emoji shortcode (GitHub, etc.) |
| [[toc]] | Table of contents (some parsers) |
| $$math$$ | Math block (LaTeX, some parsers) |
Common gotchas
- A hard line break needs two trailing spaces (or a backslash in some parsers). A single newline is collapsed into the same paragraph.
- A list or fenced code block needs a blank line before it; without one, many parsers fold it into the preceding paragraph.
- GFM tables require the
| --- |separator row — omit it and the pipes render as literal text. - Markdown is not one standard: CommonMark, GFM, and others differ on nested lists, autolinks, and the
~~/==extensions. Anything marked "some parsers" above is not portable. - Indentation is load-bearing: nested items need 2-space (or content-aligned) indentation, and 4-space-indented text silently becomes a code block.
Most of this shows up first in a project README — pair it with the Git cheat sheet.