Data Converter

A free online tool for developers, analysts, QA engineers, and businesses to convert structured data between JSON, XML, CSV, Excel, YAML, and other formats — entirely in your browser. Nothing is uploaded.

Built with Astro + vanilla TypeScript.

Features

• 8 formats — JSON, CSV, Excel, XML, YAML, HTML, Markdown, PDF
• Input methods — paste, drag & drop upload, URL fetch (with CORS proxy)
• Smart parsing — type inference, nested object flattening (_ separator), multi-sheet Excel
• Table preview — search, sort, inline edit, add/delete rows/cols, find/replace, transpose, case transforms, undo/redo, column reorder
• Export — download any format or copy to clipboard
• Tools — random data generator, Base64 encode/decode, Hex encode/decode
• Privacy — 100% client-side, no servers, no tracking
• Theme — light/dark with prefers-color-scheme support
• Persistent — history survives page refresh via localStorage

Getting Started

npm install
npm run dev

Open http://localhost:4321.

Build

npm run build
npm run preview

Output goes to dist/.

Project Structure

src/
├── components/     # Astro components (Header, InputPanel, PreviewTable, etc.)
├── layouts/        # BaseLayout with SEO meta tags
├── lib/
│   ├── converters/ # Parse/stringify for each format
│   ├── appState.ts # Reactive store with undo/redo + localStorage
│   ├── detect.ts   # Format detection + validation
│   ├── exportUtils.ts # HTML, Markdown, PDF export helpers
│   ├── theme.ts    # Light/dark theme
│   └── tools.ts    # Random data, Base64, Hex tools
├── pages/          # index.astro (tool), docs.astro, about, contact, privacy, terms, cookies, faq, 404
└── styles/         # Global CSS

License

MIT