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, with extension-specific checks for local file and image links.

💡 Recommended pairing: Use Markdown Editor v2 for syntax-aware editing and live preview, and use Markdown Lint for validation, diagnostics, and automatic fixes. The two extensions are designed to work together.

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
✅ Inline suppression - Suppress rules with <!-- markdownlint-disable-line --> comments
✅ Format Document - Auto-fix all issues via Format Document (Ctrl+K, Ctrl+D)
✅ Fix on Save - Automatically apply safe fixes whenever a Markdown document is saved
✅ Lint Folder/Solution - Lint all Markdown files in a folder, project, or solution
✅ EditorConfig support - Configure rules per-project using .editorconfig files
✅ Options page - Toggle rules on/off via Tools → Options → Markdown Lint → Rules
✅ Context menu - Quick access to enable/disable linting and settings
✅ 50+ rules - Comprehensive coverage of the supported markdownlint rules, plus local file and image link checks
✅ Works with any Markdown editor - Including the built-in Markdown editor and most Markdown extensions

Installation

1. Open Visual Studio 2022
2. Go to Extensions → Manage Extensions
3. Search for "Markdown Lint"
4. 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.

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

Context Menu

Right-click in any Markdown file to access the Markdown Lint submenu:

• Enabled - Toggle linting on/off (checkmark indicates current state)
• Settings... - Open the Rules options page directly

Lint Folder / Solution

Right-click on any folder, project, or solution in Solution Explorer to lint all Markdown files:

• Lint Markdown Files - Lint all .md files in the selected folder or project
• Lint All Markdown Files - Lint all .md files in the entire solution

Open Folder mode: When using Visual Studio's Open Folder feature (without a solution), right-click on any folder or file in the Folder View to lint all Markdown files in that location.

Results appear in the Error List window, with clickable entries to navigate directly to issues. Files are processed in parallel for fast performance. The error list is automatically cleared when you close the solution or folder.

Ignored folders: By default, common folders like node_modules, vendor, .git, bin, and obj are automatically ignored. You can customize this list in Tools → Options → Markdown Lint → General → Ignored Folders.

.markdownlintignore support: Create .markdownlintignore files at the project root or in nested folders to exclude additional files or patterns (uses .gitignore syntax). Nested patterns are relative to their containing folder and can override inherited rules.

Format Document

Use Format Document (Ctrl+K, Ctrl+D) or Format Selection (Ctrl+K, Ctrl+F) to automatically fix all auto-fixable violations. The first time you use this feature, you'll be prompted to enable or disable automatic fixing on format commands. You can change this setting later in Tools → Options → Markdown Lint → General.

Fix on Save

When Fix on Save Behavior is enabled, saving a Markdown document applies all safe auto-fixes before the file is written. The default Ask setting prompts on the first save; choose On to keep fixing on save or Off to save without changes. You can change the choice at any time in Tools → Options → Markdown Lint → General.

Configuration

Rules can be configured in two ways:

1. Options Page - Configure general settings and toggle rules via Tools → Options → Markdown Lint
2. 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.

General Options

Go to Tools → Options → Markdown Lint → General to configure:

Rules Options

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

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

The default severity for all rules is warning.

Available severity levels:

• error - Shown as error (red squiggle)
• warning - Shown as warning (green squiggle) [default]
• suggestion - Shown as suggestion/hint (gray dots)
• 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

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:

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
• Convert all [style] to [target] style - Normalize emphasis, strong, or list marker style across the entire document
• Fix all auto-fixable violations in document - Fix all auto-fixable issues at once

Inline Suppression

Suppress specific rules directly in your Markdown files using HTML comments, compatible with the standard markdownlint suppression syntax.

Suppressing Errors

There are multiple ways to suppress an error:

1. From QuickInfo - Hover over an error and click the "Suppress in code" link
2. From Error List - Right-click an error in the Error List and select "Suppress in code"
3. Manually - Type <!-- markdownlint-disable-line --> and use IntelliSense to add rule codes

Suppression Comment Syntax

<!-- markdownlint-disable-line MD013 -->
This line is excluded from the MD013 (line length) rule.

<!-- markdownlint-disable-line MD013 MD033 -->
This line is excluded from multiple rules.

<!-- markdownlint-disable MD013 -->
All lines below are excluded from MD013...
<!-- markdownlint-enable MD013 -->

<!-- markdownlint-disable-next-line MD041 -->
The next line is excluded from MD041.

<!-- markdownlint-disable-file MD013 -->
The entire file is excluded from MD013.

IntelliSense Support

When typing suppression comments, IntelliSense provides:

• Rule code completion - Type MD to see all available rule codes (MD001, MD003, etc.)
• Rule name completion - Type the rule name like heading-increment or line-length
• QuickInfo tooltips - Hover over rule codes in suppression comments to see the rule description

Supported Directives

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.