Markdown is the lightweight markup language used everywhere from GitHub to Reddit to Notion. This cheat sheet covers the 20 syntax rules that handle 95% of everyday writing.
1. Headings
Use # for h1, ## for h2, up to ###### for h6. Leave a space after the hash:# Big title## Smaller title
2. Emphasis
*italic* or _italic_ for italics**bold** or __bold__ for bold~~strikethrough~~ for strikethrough (GFM)
3. Lists
Unordered: start lines with -, *, or +
Ordered: 1., 2., etc.
Nested: indent 2 or 4 spaces.
4. Links and images
Link: [text](https://example.com)
Image: 
5. Code
Inline: `code` with backticks
Block: ```language on three lines, your code, then ```
6. Tables (GFM)
| Name | Age |
|-------|-----|
| Alice | 30 |
| Bob | 25 |
7. Blockquotes and horizontal rules
Blockquote: start with >
Horizontal rule: three or more dashes ---, asterisks ***, or underscores ___
8. How to preview
Open the Markdown Preview, type or paste Markdown on the left, and see the rendered HTML on the right in real time. Useful for drafting READMEs or blog posts.