The quick answer: Start a line with one or more hash symbols (
#) followed by a space and your heading text.
The Six Heading Levels
# Heading 1 — the largest, usually the page title (use once per document)
## Heading 2 — major sections
### Heading 3 — sub-sections
#### Heading 4, ##### Heading 5, ###### Heading 6 — deeper levels (use sparingly)The number of # symbols determines the heading level. H1 is the largest, H6 is the smallest.
The Space is Required
#Heading will not render as a heading. The space between the # and the heading text is required in CommonMark. Always write # Heading, not #Heading.
Alternative Syntax (Setext Style)
H1 and H2 can also be written by underlining with = or -:
Heading 1
=========
Heading 2
---------
This is the older Setext style. Most people use the # hash style today — it's clearer and supports all six levels.
Heading Anchors
Every heading automatically gets an anchor ID for internal linking. ## Getting Started gets the anchor #getting-started. Use this in links: [Go to Getting Started](#getting-started).
Need to generate a full table of contents from your headings? Try the free TOC generator.
Best Practices
- Use only one H1 per document (the main title)
- Don't skip levels — go H2 → H3, not H2 → H4
- Keep headings short and descriptive — they appear in tables of contents and anchor links
Full reference: Markdown Headings.