Free · open source · runs in your browser
A browser-based markdown editor with live preview. Supports GitHub Flavored Markdown, Mermaid diagrams, KaTeX / LaTeX math, and syntax-highlighted code — rendered entirely in your browser. No server, no account, no tracking.
$…$ and block $$…$$. Full LaTeX math-mode.
Yes — free and open source under the MIT license. Every feature is available without payment, sign-up, or email capture.
Yes. After the first page load, MarkdownLab runs entirely in your browser. Documents persist in IndexedDB and survive reloads and browser restarts.
Completely. No backend, no analytics, no cookies. Documents never leave your device. You can verify the source on GitHub.
GitHub Flavored Markdown (GFM) via the marked parser, plus heading-ID and footnote extensions.
Yes — any fenced block tagged mermaid renders as an interactive diagram with pinch / wheel / keyboard zoom and PNG export.
Yes, via KaTeX. Use $…$ for inline math and $$…$$ for block math.
Export → Download PDF uses the browser's native print engine for crisp vector output with real pagination and working hyperlinks.
Any modern browser with ES Modules support: Chrome, Firefox, Safari, Edge, Brave, and Arc, on desktop and mobile.