This is a quick reference card for markdown syntax. Save it, bookmark it, and come back when you need to remember how to format something.

Basic Formatting

Element	Syntax	Output
Heading 1	`# Heading`	Largest heading
Heading 2	`## Heading`	Larger heading
Heading 3	`### Heading`	Medium heading
Bold	`bold`	bold
Italic	`italic`	italic
Bold + Italic	`*text*`	text
Strikethrough	`~~strikethrough~~`	~~strikethrough~~
Inline code	`code`	`code`
Line break	Two spaces at end of line	New line, same paragraph
Horizontal rule	`---` or `***`	Visual divider

Lists

Element	Syntax
Bullet list	`- item` or `* item`
Numbered list	`1. item`
Nested list	`- indented item` (2 spaces)

Example:

- First item
  - Nested item
- Second item

Links and Images

Element	Syntax	Example
Link	`[text](url)`	`[OpenMark](https://openmarkapp.com)`
Link with title	`[text](url "title")`	`[OpenMark](https://openmarkapp.com "Native Mac editor")`
Image	`![alt](url)`	`![App icon](icon.png)`
Image with link	`[![alt](img)](link)`	Click image to follow link

Code Blocks

Inline code:

Use `variable` in the sentence.

Code block (three backticks):

code here

Code block with language (for syntax highlighting):

function example() {
  return "syntax highlighted";
}

Blockquotes

Single line:

> This is a quote.

Multi-line:

> First line of quote.
> Second line of quote.

Nested:

> First level quote.
>> Nested quote.

Tables (GitHub Flavored Markdown)

| Header 1 | Header 2 |
|----------|----------|
| Cell 1   | Cell 2   |
| Cell 3   | Cell 4   |

Alignment:

| Left | Center | Right |
|:-----|:------:|------:|
| L    | C      | R     |

Left	Center	Right
L	C	R

Task Lists (GitHub Flavored Markdown)

- [x] Completed task
- [ ] Incomplete task
- [ ] Another task to do

Renders as:

Completed task
Incomplete task
Another task to do

Footnotes

This is text with a footnote[^1].

[^1]: This is the footnote content.

The footnote appears at the bottom of the document and is automatically linked.

Escaping Characters

If you need to display a markdown symbol literally (not as formatting), use a backslash:

\# This will show a # symbol, not a heading.
\*\*Not bold\*\*

HTML

If markdown doesn't support something, you can embed HTML:

<div style="color: red;">This text is red.</div>

Extended Syntax: LaTeX Math

Some markdown viewers (including OpenMark) support LaTeX math notation:

Inline: $E = mc^2$

Block:

$$
\frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
$$

Extended Syntax: Mermaid Diagrams

OpenMark and other markdown viewers support Mermaid for flowcharts, sequence diagrams, and charts:

graph TD
  A[Start] --> B[Process]
  B --> C[End]

Common Markdown Tools for Mac

Tool	Purpose
OpenMark	View markdown with LaTeX and Mermaid support
VS Code	Write markdown with live preview
iA Writer	Minimalist markdown writing
Bear	Note-taking with markdown support
Obsidian	Knowledge management in markdown

Pro Tips

Use relative links in markdown projects. Instead of full URLs, use [link](/blog/post-name) to link between pages.
Write one sentence per line in version control. It makes diffs cleaner when you collaborate.
Use semantic formatting. Bold for emphasis, not size. Headings for structure, not styling.
Test your markdown in multiple viewers. GitHub, Notion, and VS Code may render things slightly differently.
Keep it simple. Basic markdown is more portable than complex extensions.

For a guide on writing markdown from scratch, see How to Write Markdown: A Beginner's Guide.

For practical uses of markdown (meeting notes, students, developers), explore Markdown for Students or Markdown for Developers.

Download OpenMark → — $9.99, one-time, native macOS. View markdown with perfect formatting. Supports LaTeX, Mermaid, tables, task lists, and all GitHub Flavored Markdown extensions.