Markdown Formatter
Paste Markdown and get it back formatted by Prettier: one list style, aligned tables, consistent headings, and tidy YAML frontmatter. Formatting runs in your browser, and the result opens in an editor with a Raw view and a Preview you can type in.
What Prettier changes in a Markdown file
Prettier changes the layout of a Markdown file, not its words. List items get one marker style, headings use # markers, blocks are separated by one blank line, and table columns line up. The YAML frontmatter at the top of the file is formatted too.
Long lines are not rewrapped, and inline HTML or XML-like tags such as <example> keep their lines. A diff after formatting shows layout changes, so it is safe to run on a README, a docs page, or a Claude skill file before you commit it.
Format on paste, on open, and on command
In the editor, Prettify formats a Markdown document when you paste it or open a file, and the Format command runs Prettier again after you edit. Open .md and .markdown files from the file picker or by drag and drop. The macOS app also opens them from Finder.
Files of 200 KB or more open as they are, because Prettier runs in the page and would pause it on a large file. Use the Format command when you want a large file formatted.
Private by design
Prettier runs in your browser. Your Markdown is not uploaded to a server to be formatted, so internal docs, notes, and unreleased changelogs stay on your device. Prettier loads the first time you format Markdown, so pages that never need it stay light.
Frequently asked questions
Which formatter does this page use?
Prettier, with its Markdown and YAML plugins. It is the formatter that many code editors and CI checks use, so the output matches what Prettier gives you in a project with default settings.
Will formatting change my text?
No. Prettier changes layout only: list markers, heading markers, spacing, blank lines, and table alignment. Your words and links stay the same, and long lines are not rewrapped.
Is the Markdown formatter free?
Yes. Formatting, the Raw view, the editable Preview, and the frontmatter Properties card are free with no sign-up. A one-time Pro purchase adds Side by side editing, the Outline, Mermaid diagrams in the Preview, Skill Check, and export.
Is my Markdown uploaded to a server?
No. Formatting runs locally in your browser. The document leaves your device only if you create a share link yourself.
Can I format MDX here?
Use the MDX formatter for .mdx files. It uses Prettier's MDX parser, keeps imports, exports, and JSX as written, and keeps the whole file as written when formatting would change how MDX reads it.