Markdown Formatter and Linter

Clean, validate, and optimize your Markdown documents. This tool runs entirely offline in your browser - your content never leaves your device.

Input Markdown

0 chars, 0 lines

Indentation

Line Endings

Format tables

Consistent header style

Remove trailing whitespace

Formatted Output

Issues Found

Readability Score

Markdown Presets

Mastering Markdown Quality

Why Format and Lint Markdown?

Consistent Markdown improves readability, reduces merge conflicts in version control, and ensures your documentation renders correctly across different platforms. Formatting standardizes spacing, indentation, and structure while linting catches common errors and style violations.

Step-by-Step Guide

Paste your Markdown into the input area
Configure formatting options for your project's style guide
Review the formatted output and linting results
Apply fixes manually or use the formatted version directly
Copy the cleaned Markdown to your clipboard

Examples

Example 1: Inconsistent Headers

Before:

#Header 1

##  Header 2 with extra spaces

###Header 3 no space

After:

# Header 1

## Header 2 with extra spaces

### Header 3 no space

Example 2: Table Formatting

Before:

|Column1|Column 2|Column3|
|---|---|---|
|data1|data two|data3|
|longer data|short|medium|

After:

| Column1      | Column 2 | Column3 |
| ------------ | -------- | ------- |
| data1        | data two | data3   |
| longer data  | short    | medium  |

Frequently Asked Questions

What are the input size limits?

The tool can handle documents up to 100,000 characters. For larger documents, consider processing in sections for optimal performance.

How accurate is the readability score?

The score uses simple heuristics based on average sentence length and syllable count. It's best used for relative comparisons rather than absolute measurements.

Does this support all Markdown flavors?

The tool focuses on CommonMark with extensions for tables and strikethrough. Some niche syntax from specific implementations may not be fully supported.

Can I use this for code documentation?

Yes! The technical docs preset is optimized for code documentation with strict linting rules that help maintain consistency across large projects.

Formulas & Assumptions

Readability Score: Flesch Reading Ease = 206.835 - (1.015 × ASL) - (84.6 × ASW) where ASL = average sentence length, ASW = average syllables per word

Table Formatting: Columns are sized to fit content with 1-3 spaces padding based on header/content length ratios

Header Consistency: ATX-style headers (#) with exactly one space between # and text, no trailing #

Line Ending Normalization: CRLF (Windows) or LF (Unix) based on selection, consistent throughout document

Disclaimer: For informational and educational purposes only. All processing occurs locally in your browser. For compliance critical workflows verify results with official standards or professional tools.

Sources: CommonMark Specification, GitHub Flavored Markdown, Flesch Reading Ease Formula, Unicode Standard

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