Markdown Lint for Visual Studio

A powerful Visual Studio extension that brings real-time Markdown linting to your editor, based on the popular markdownlint rules (MD001-MD058).

Features

✅ Real-time linting - See issues as you type with squiggly underlines
✅ Error List integration - All warnings appear in Visual Studio's Error List
✅ Quick fixes - Press Ctrl+. for automatic fixes (light bulb suggestions)
✅ Fix All support - Fix all violations of a rule or all auto-fixable issues at once
✅ EditorConfig support - Configure rules per-project using .editorconfig files
✅ Options page - Toggle rules on/off via Tools → Options → Markdown Lint → Rules ✅ 50+ rules - Comprehensive coverage based on markdownlint standards

Installation

Open Visual Studio 2022
Go to Extensions → Manage Extensions
Search for "Markdown Lint"
Click Download and restart Visual Studio

Or download directly from the Visual Studio Marketplace.

Getting Started

Once installed, the extension works automatically on any .md file. It is compatible with both the built-in Markdown editor in Visual Studio and the Markdown Editor v2 extension.

Open a Markdown file
Linting issues appear as squiggly underlines
Hover over issues to see the rule description
Press Ctrl+. on an issue to see available quick fixes
Check the Error List (Ctrl+\, E) for all issues in the document

Configuration

Rules can be configured in two ways:

Options Page - Toggle rules on/off via Tools → Options → Markdown Lint → Rules
EditorConfig - Configure rules per-project using .editorconfig files

EditorConfig settings take precedence over the Options page. If no EditorConfig rule exists for a specific rule, the Options page setting is used.

Options Page

Go to Tools → Options → Markdown Lint → Rules to access all rule settings organized by category:

Category	Rules
1. Headings	MD001, MD003, MD018-MD026, MD041
2. Lists	MD004, MD005, MD007, MD029, MD030, MD032
3. Whitespace	MD009, MD010, MD012, MD013, MD047
4. Code Blocks	MD014, MD031, MD040, MD046, MD048
5. Links	MD011, MD034, MD039, MD042, MD045, MD051-MD054
6. Inline	MD033, MD035-MD038, MD049, MD050
7. Blockquotes	MD027, MD028
8. Tables	MD055, MD056, MD058

Changes take effect immediately when you click OK or Apply - all open markdown files are automatically revalidated.

EditorConfig

Rules can also be configured in your .editorconfig file. All rules use the md_ prefix.

💡 Tip: Install the EditorConfig Language Service extension to get IntelliSense and validation for markdown lint rules in your .editorconfig files.

Example .editorconfig

[*.md]
# Disable trailing spaces rule
md_no_trailing_spaces = false

# Set line length to 120 characters
md_line_length = 120

# Change severity to error
md_no_hard_tabs = true:error

# Change severity to suggestion
md_no_multiple_blanks = true:suggestion

# Use specific heading style with warning severity
md_heading_style = atx:warning

Severity Levels

Severity is specified after the value using a colon: rule = value:severity

md_no_trailing_spaces = true:error
md_line_length = 120:suggestion
md_heading_style = atx:warning

Available severity levels:

error - Shown as error (red squiggle)
warning - Shown as warning (green squiggle) [default]
suggestion - Shown as suggestion/hint
silent - Rule runs but doesn't report
none - Rule is disabled

To disable a rule entirely, set the value to false:

md_no_trailing_spaces = false

Available Rules

EditorConfig Property	Rule	Description
`md_heading_increment`	MD001	Heading levels should only increment by one level at a time
`md_heading_style`	MD003	Heading style (atx, atx_closed, setext, consistent)
`md_ul_style`	MD004	Unordered list style (asterisk, plus, dash, consistent)
`md_list_indent`	MD005	Inconsistent indentation for list items at the same level
`md_ul_indent`	MD007	Unordered list indentation (default: 2 spaces)
`md_no_trailing_spaces`	MD009	Trailing spaces not allowed
`md_no_hard_tabs`	MD010	Hard tabs not allowed
`md_no_reversed_links`	MD011	Reversed link syntax
`md_no_multiple_blanks`	MD012	Multiple consecutive blank lines
`md_line_length`	MD013	Line length (default: 80 characters, disabled by default)
`md_commands_show_output`	MD014	Dollar signs used before commands without showing output
`md_no_missing_space_atx`	MD018	No space after hash on atx style heading
`md_no_multiple_space_atx`	MD019	Multiple spaces after hash on atx style heading
`md_no_missing_space_closed_atx`	MD020	No space inside hashes on closed atx style heading
`md_no_multiple_space_closed_atx`	MD021	Multiple spaces inside hashes on closed atx style heading
`md_blanks_around_headings`	MD022	Headings should be surrounded by blank lines
`md_heading_start_left`	MD023	Headings must start at the beginning of the line
`md_no_duplicate_heading`	MD024	Multiple headings with the same content
`md_single_title`	MD025	Multiple top-level headings in the same document
`md_no_trailing_punctuation`	MD026	Trailing punctuation in heading
`md_no_multiple_space_blockquote`	MD027	Multiple spaces after blockquote symbol
`md_no_blanks_blockquote`	MD028	Blank line inside blockquote
`md_ol_prefix`	MD029	Ordered list item prefix (one, ordered, one_or_ordered, zero)
`md_list_marker_space`	MD030	Spaces after list markers
`md_blanks_around_fences`	MD031	Fenced code blocks should be surrounded by blank lines
`md_blanks_around_lists`	MD032	Lists should be surrounded by blank lines
`md_no_inline_html`	MD033	Inline HTML not allowed (disabled by default)
`md_no_bare_urls`	MD034	Bare URL used
`md_hr_style`	MD035	Horizontal rule style (consistent, ---, ***, ___)
`md_no_emphasis_as_heading`	MD036	Emphasis used instead of a heading (disabled by default)
`md_no_space_in_emphasis`	MD037	Spaces inside emphasis markers
`md_no_space_in_code`	MD038	Spaces inside code span elements
`md_no_space_in_links`	MD039	Spaces inside link text
`md_fenced_code_language`	MD040	Fenced code blocks should have a language specified
`md_first_line_heading`	MD041	First line in a file should be a top-level heading (disabled by default)
`md_no_empty_links`	MD042	No empty links
`md_required_headings`	MD043	Required heading structure (disabled by default)
`md_proper_names`	MD044	Proper names should have correct capitalization (disabled by default)
`md_no_alt_text`	MD045	Images should have alternate text (alt text)
`md_code_block_style`	MD046	Code block style (fenced, indented, consistent)
`md_single_trailing_newline`	MD047	Files should end with a single newline character
`md_code_fence_style`	MD048	Code fence style (backtick, tilde, consistent)
`md_emphasis_style`	MD049	Emphasis style (asterisk, underscore, consistent)
`md_strong_style`	MD050	Strong style (asterisk, underscore, consistent)
`md_link_fragments`	MD051	Link fragments should be valid
`md_reference_links_images`	MD052	Reference links and images should use a label that is defined
`md_link_image_reference_definitions`	MD053	Link and image reference definitions should be needed
`md_link_image_style`	MD054	Link and image style
`md_table_pipe_style`	MD055	Table pipe style (leading_and_trailing, consistent)
`md_table_column_count`	MD056	Table column count should be consistent
`md_blanks_around_tables`	MD058	Tables should be surrounded by blank lines

Rule Documentation

For detailed documentation on each rule, see the markdownlint Rules Documentation.

Quick Fixes

The extension provides intelligent quick fixes (Ctrl+.) for many common issues:

Rule	Quick Fix
MD009	Remove trailing whitespace
MD010	Replace tabs with spaces
MD011	Fix reversed link syntax
MD012	Remove extra blank lines
MD018	Add space after heading hash
MD019/MD021/MD027	Normalize multiple spaces
MD022/MD031/MD032/MD058	Add blank lines around elements
MD023	Remove leading whitespace from headings
MD026	Remove trailing punctuation
MD034	Wrap bare URLs in angle brackets
MD040	Add language identifier to code blocks
MD045	Add alt text placeholder to images
MD047	Add/remove trailing newline

Fix All Actions

Right-click on any fixable issue to access bulk fix options:

Fix all [rule] violations in document - Fix all instances of a specific rule
Fix all auto-fixable violations in document - Fix all auto-fixable issues at once

Contributing

Found a bug or have a feature request? Please open an issue on GitHub.

License

This extension is open source. See the LICENSE file for details.

Markdown Lint

Mads Kristensen