Beautiful markdown, rendered instantly.
Paste it, drop it, or link it — any markdown file, typeset in your browser. No ads, no sign-up, nothing uploaded.
The web is full of "markdown preview" sites wrapped in ads and cookie banners. RenderMD is the opposite: a fast, private, genuinely beautiful place to read and write markdown.
- Bring anything — paste, drop a file anywhere on the page, open from disk, or load a URL. GitHub repos, files and gists are converted to raw automatically, and relative images keep working:
render-md.com/?url=github.com/owner/repo. - Read it beautifully — three typesets (Modern, Editorial, Technical), adjustable size and line length, an outline, reading progress, light and dark themes.
- Everything renders — GitHub Flavored Markdown, GitHub alerts, footnotes, emoji shortcodes, YAML frontmatter, safe raw HTML (
<details>,<kbd>, centered images…), KaTeX math, every Mermaid diagram type (with an optional hand-drawn look), and syntax highlighting for 200+ languages. - Share privately — a share link is the document, compressed into the URL fragment, which browsers never send to a server.
- Take it with you — copy as formatted text (pastes cleanly into Docs, Gmail, Notion), save
.mdback to the file you opened, export a standalone.html, or print to PDF. - Write comfortably — CodeMirror 6 with a formatting toolbar and shortcuts, line-accurate scroll sync, double-click the preview to jump to the source, tick task boxes right in the preview, a command palette (⌘K), and Undo for every document swap.
- Installable — as a PWA it can register as an "Open with…" handler for
.mdfiles.
The markdown cheat sheet covers every syntax — CommonMark, GFM and beyond — with live examples you can edit in place, compatibility notes, a printable quick reference and an FAQ. Every example is rendered by the same engine as the editor.
Markdown is rendered off the main thread in a Web Worker by a unified pipeline (remark → rehype, sanitized with GitHub's rules), then turned into React with hast-util-to-jsx-runtime. Code is highlighted lazily with Shiki (JS regex engine, per-language code splitting), math with KaTeX, diagrams with Mermaid. Documents live in localStorage; nothing about them ever reaches the server.
| Layer | Technology |
|---|---|
| Framework | TanStack Start · React 19 (Activity, React Compiler) |
| Build | Vite 8 (Rolldown) · Nitro → Cloudflare Workers |
| Language | TypeScript 7 (native compiler) |
| Quality | Oxlint (type-aware) · Oxfmt · Vitest 5 |
| Styling | Tailwind CSS 4 · shadcn/ui on Base UI · Hanken Grotesk, Newsreader, Geist Mono |
| Editor | CodeMirror 6 |
| Rendering | unified / remark / rehype in a Web Worker · Shiki · KaTeX · Mermaid |
Requires Node 24 (see .node-version) and pnpm.
pnpm install
pnpm dev # http://localhost:3000| Command | What it does |
|---|---|
pnpm dev |
Dev server on port 3000 |
pnpm build |
Production build for Cloudflare Workers (.output/) |
pnpm test |
Unit tests (Vitest) |
pnpm check |
Format check, type-aware lint and typecheck — what CI runs |
pnpm fix |
Format and auto-fix lint issues |
pnpm deploy |
Deploy the build with Wrangler |
See AGENTS.md for an architecture tour and the design system.
pnpm build produces a Cloudflare module worker via Nitro (nitro.config.ts). CI deploys main automatically and uploads a preview version for every pull request. To target another host, change the Nitro preset.
MIT — see LICENSE.