Online Markdown Editor
Edit Markdown the way it reads, or as plain text, and switch between the two at any time. Prettify opens .md files in an editable WYSIWYG Preview, a Raw view with syntax highlighting, and a Properties card for the YAML frontmatter. It runs in your browser and as a native macOS app.
WYSIWYG without losing your Markdown
Many rich text editors rewrite Markdown when they save it: list markers change, tables lose their alignment, and inline HTML disappears. The Prettify Preview keeps your text exactly. When it cannot do that for a document, it opens read-only with a notice, so an edit never changes lines you did not touch.
The Raw view shows the source with syntax highlighting. Prettier formats the document when you paste or open it, and the Format command runs it again whenever you want.
Edit frontmatter field by field
Static site generators, docs tools, and Claude skills keep their settings in YAML frontmatter. Prettify shows that block as a Properties card: a text field for each value, a checkbox for true and false, and a YAML mode to edit the block as text.
If the frontmatter is not valid YAML, the Problems panel shows the error with its line, and a click jumps to it. This makes the editor a good fit for a SKILL.md, where a broken name or description stops the skill from loading as you expect.
Open files from anywhere, keep them private
Open a file by paste, file picker, or drag and drop. The macOS app also opens .md, .markdown, and .mdx files from Finder. Editing runs on your device, and your documents are not uploaded to a server.
Frequently asked questions
Is this a WYSIWYG Markdown editor?
Yes. The Preview is an editor: type in it like a document, and the Markdown source follows. The Raw view is there when you want to edit the source directly.
Will the editor change my formatting?
Prettier formats the document when you paste or open it, so list markers and table spacing follow one style. After that, the Preview keeps your text exactly, and it opens read-only for a document it cannot keep exactly.
Can I edit YAML frontmatter?
Yes. The Properties card lets you edit each field, switch true and false values with a checkbox, or edit the whole block as YAML. Invalid YAML shows in the Problems panel with its line.
Is the Markdown editor free?
Yes. Editing in the Preview and the Raw view, Prettier formatting, and the Properties card are free with no sign-up. Pro, a one-time purchase, adds Side by side, the Outline, Mermaid diagrams, Skill Check, and HTML and PDF export.
Is there a desktop app?
Yes. The native macOS app has the same editor and opens .md, .markdown, and .mdx files from Finder.
Can I convert Markdown to JSON or YAML?
No. Markdown is a text document in Prettify, not data, so it does not convert to JSON, YAML, CSV, or XML. Pro can export a Markdown document as HTML, or as PDF on the web.