MD020 - No missing space in closed heading
November 28, 2025 · View on GitHub
Aliases: no-missing-space-closed-atx
What this rule does
Ensures there's a space after the opening # and before the closing # in headings that use # symbols at both ends.
Why this matters
- Readability: Spaces make the heading text easier to read
- Compatibility: Some Markdown processors require spaces for proper rendering
- Consistency: Maintains uniform heading formatting
Examples
✅ Correct
# Heading 1 #
## Heading 2 ##
### Heading 3 ###
#### Heading 4 ####
##### Heading 5 #####
###### Heading 6 ######
❌ Incorrect
#Heading 1#
##Heading 2##
###Heading 3###
#Heading 4 #### (missing space at start)
##### Heading 5##### (missing space at end)
🔧 Fixed
# Heading 1 #
## Heading 2 ##
### Heading 3 ###
#### Heading 4 ####
##### Heading 5 #####
Configuration
This rule has no configuration options.
Automatic fixes
This rule automatically adds spaces where they're missing:
- After the opening # symbols
- Before the closing # symbols
Learn more
- CommonMark specification for headings - Technical details about heading syntax
- Closed headings - Alternative heading syntax