⌘ K
Prettier-style rules · normalize heading spacing, lists, emphasis

Auto-format Markdown documents

One-pass formatter that normalizes heading spacing, list markers, emphasis style, and trailing whitespace — Prettier-aligned defaults.

Markdown Formatter
Input
122 B
20 lines
Output
117 B
16 lines
Status
ready
live
Ratio
0.96×
out/in
input · markdown
output · formatted
#Title

- one
- two
- three

**bold** and *italic*

## Heading with extra spaces

```js
console.log("hi");
```

End.
Quick Start

How to format Markdown

Applies Prettier-compatible Markdown rules: one space after #, - for unordered lists, ** for bold, collapse multi-blank-line runs, preserve hard breaks and code fences.

  1. 01

    Paste Markdown

    Inconsistent drafts welcome.

    Parsing runs through marked with GFM extensions enabled — tables, task lists, strikethrough, and fenced code blocks all match GitHub’s rendering.

    inputGFMmarkedCommonMarklive
    input · markdownmd · GFM
    #Title
* a
    loaded · GFMGFM · ready
  2. 02

    Normalize syntax

    Headings, lists, and emphasis get canonical markers.

    Soft-break behaviour is configurable: by default a single newline becomes a space (CommonMark), toggle on for chat-style <br> insertion.

    normalizesoft-breaksoptionsconfiglive
    fix · optionsrules · live
    # Title
- a
    options applied · livelive
  3. 03

    Collapse blanks

    3+ blank lines collapse to one blank line.

    The preview is scoped under a .mde class so its CSS doesn’t bleed into the rest of the page. Output HTML is whitespace-controlled for clean diffs.

    collapsepreviewscoped CSSrenderstable
    out · renderedtight · ready
    # T

- a
    rendered · liverendered
  4. 04

    Commit

    One canonical style across your repo.

    Export covers both raw Markdown and rendered HTML; downloads stream as text/markdown or text/html via Blob + object URL.

    exportclipboard.md.htmlblob
    ✓ · exportedmd · done
    ✓ formatted
    shipped · ready to shipsuccess
Pro tips

Author Markdown that renders everywhere

GFM is the safe default

GitHub-Flavored Markdown is the de-facto baseline (tables, task lists, strikethrough). CommonMark is stricter but ubiquitous as a fallback.

Soft-break behaviour varies

A single newline is a space in CommonMark, a <br> in GFM. Toggle soft breaks when source matters.

Escape inside code fences

Backticks inside fenced blocks need a longer fence — three becomes four. Use ~~~ if your content has many backticks.

Anchors are slugified

GitHub lowercases, strips punctuation, and joins with hyphens. Duplicate headings get -1, -2 suffixes.

Tables need a header row

The dash row sets alignment (:---, :-:, ---:). Use Table Aligner for diff-friendly columns.

Front matter is YAML

Triple-dash blocks at the top of files are parsed by static-site generators. Use the Front-Matter Validator to catch syntax errors.

Related toolsLinterMinifierStyleTable AlignerHeading LevelerEditor
Use Cases

When to format Markdown

Enforce one style so diffs only show real changes.

Pre-commit

Run as a pre-commit step alongside Prettier. Render path uses marked with GFM extensions enabled (tables, task lists, strikethrough, autolinks), so what you preview matches what GitHub publishes bit-for-bit. Soft-break behaviour is configurable for chat-style vs prose Markdown.

GFM-compliant

Team repos

Eliminate style bikeshedding across contributors. Pairs cleanly with the Markdown Cheatsheet for syntax you can't quite remember — callout blocks, footnotes, definition lists. Output stays diff-friendly so style-only changes don't drown out real edits in PRs.

GitHub-perfect

Doc imports

Normalize imports from various Markdown sources. Cross-platform safe: anchors, code fences, and tables behave identically on GitHub, GitLab, Bitbucket, and Gitea. Heading-anchor slugs follow GitHub's lowercase-and-hyphenate rules so deep links survive a docs migration.

diff-friendly

Static-site builds

Catch style drift before SSG renders. No server roundtrip — perfect for proprietary content you can't paste into a public tool. The full marked + GFM bundle ships with the page, so it works offline once loaded.

render-stable

Audit prep

Run before doc audits to remove cosmetic noise. Front matter (YAML / TOML / JSON) passes through unchanged so static-site pipelines (Jekyll, Hugo, Astro, Eleventy) read it correctly. Pair with the Front-Matter Validator to catch syntax errors before deploy.

cross-platform

PR diff hygiene

Smaller, focused PR diffs. Output is reproducible: identical input always produces identical Markdown, so doc-generation scripts can rely on it for snapshot tests and embedded into release workflows.

SEO-friendly
FAQ

Frequently asked questions

Heading: one space after #. Lists: -, *, + all become -. Emphasis: __ becomes **. Trailing spaces removed (hard breaks preserved). 3+ blank lines collapsed to 2.
No — anything inside ``` is preserved verbatim.
Mostly. Prettier's full Markdown formatter does more (line wrapping, table alignment), but this output should round-trip cleanly through Prettier.
No — use the Table Aligner tool for that.
No. Formatting runs locally in your browser.
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