Why this site exists
Developers and writers often need to reshape API responses, config files, or spreadsheet exports into a different format — quickly, and without friction. Many existing online converters are capable, but pasting real work data into them can feel risky. FormatArc was built to offer a simple "paste, convert, close" experience that you can use with confidence.
Your data never leaves your browser
Every conversion runs entirely inside your browser. Input data is never sent to FormatArc's servers or to any third-party service. Whether you're working with API keys, internal data, or files containing personal information, nothing travels over the network. The site itself is served as static files, with no backend that could receive your input.
What's next
We'll keep adding small, focused tools around JSON, YAML, CSV, Markdown, and HTML conversion, along with blog articles that cover the practical side of each format.
Open source and CLI
FormatArc's conversion logic is open source under the MIT License. The same converters are available on the command line via npm install -g formatarc, so you can use them inside CI/CD pipelines or on machines where opening a browser isn't an option. Source code: https://github.com/m-naoki-m/formatarc — npm package: https://www.npmjs.com/package/formatarc — the Chrome extension lives in the same repository as well.
Contact
For questions, feedback, or bug reports, please email info@m-naoki-m.com.