A polished markdown editor with real-time preview, syntax highlighting, diagrams and math.
16+ languages via Shiki with One Dark Pro theme. Same engine as VS Code.
Flowcharts, sequence, ER, Gantt, class diagrams and more — rendered live.
Inline and display LaTeX math. Equations, matrices, integrals and more.
Real-time diagnostics via remark-lint with one-click auto-fix.
Private by architecture
Your documents are saved in IndexedDB — nothing is transmitted, stored, or processed on any server. Zero tracking, zero cookies.
No accounts, no lock-in
Open the editor and start writing. No signup, no subscriptions, no vendor lock-in. Your data stays under your control.
Built with modern tech
Astro, CodeMirror 6, Shiki, and Tailwind CSS. Fast, lightweight, and works offline once cached.
Free & open source
MIT licensed. No premium tiers, no paywalls. Full source on GitHub.
Yes, CodeInk is 100% free and open source. There are no premium tiers, no paywalls, and no feature restrictions. The full source code is available on GitHub.
No. Zero signup required. Open the editor and start writing. Your documents are saved locally in your browser via IndexedDB.
Your documents never leave your browser. CodeInk runs 100% client-side with zero tracking and zero cookies. Nothing is stored on any server.
Yes. CodeInk renders Mermaid diagrams in real-time directly in the preview pane. Supported types include flowcharts, sequence diagrams, ER diagrams, Gantt charts, class diagrams, and more. Learn more in our Mermaid diagrams guide.
Yes. CodeInk supports KaTeX for rendering LaTeX math expressions inline and in display mode. Check out our KaTeX math guide for syntax examples.