Markdown Preview is a free, private Markdown editor with a live preview. Everything stays on your device (IndexedDB), so there is no sign-up and no server storing your notes.

Features:

- GitHub Flavored Markdown, callouts, footnotes, frontmatter

- KaTeX math and Mermaid diagrams

- Syntax highlighting for 180+ languages

- Present mode: turn any doc into slides with speaker notes

- Open GitHub/GitLab files straight from a link

- Tabs, outline, auto snapshots, custom CSS

- Export to PDF, HTML or .md, or copy as rich text into Gmail, Docs or Slack

- Installable PWA, works offline

Free, no tiers, no watermark.