About JSON Studio
Fourteen JSON tools that run entirely in your browser, built and maintained in the open by one person, on the principle that a utility should not require you to hand over your data to use it.
Why it exists
Most free JSON tools want your payload on their server first. For a formatter that is absurd, and for anything carrying customer data, credentials or an API response from a production system, it is a genuine problem — the kind that turns "let me just format this quickly" into a policy question.
JSON Studio was built the other way round: no backend at all. That single constraint decides everything else. Nothing can leak because nothing is transmitted; there is no account because there is nothing to attach one to; it works offline because it never needed the network; and it is free permanently because there is no server bill to cover.
Who builds it
Suthahar Jegatheesan — a Senior Solutions Architect working in Azure, AI and mobile architecture, writing at MSDEVBUILD and on YouTube. The tools came out of the day job: reading raw API responses and configuration files all day gets old, and the good tooling for it either costs money or wants an upload.
Find him on LinkedIn or GitHub.
How it is built
Plain HTML, CSS and JavaScript. No framework, no build step, no bundler — you can clone the repository and open index.html, and what you read in the source is exactly what runs in the browser. That is partly taste and partly the point: a privacy claim you can verify by reading the code is worth more than one you have to trust.
The only third-party runtime dependencies are D3 on the diagram page and js-yaml on the YAML converter. Everything else — the CSV parser, the JSONPath evaluator, the schema inference, the validator, the code generators — is written from scratch, in part so that no library can quietly change what happens to your data.
Principles
- Your data never leaves your browser. Everything else is negotiable; this is not.
- No sign-up wall. Open the page and use the tool.
- Say what it actually does. Where a tool infers or approximates, the page says so rather than implying certainty.
- Work offline. Install it and the whole toolkit runs with no connection.
- Stay readable. Anyone should be able to open the source and follow it.
Contributing
The project is open source and contributions are welcome — a new tool, a fix, or better wording. The contributing guide in the repository covers the layout, the shared toolkit that handles the boilerplate, and the design tokens. If a tool you need is missing, that guide is the fastest route to having it.
Contact
Ideas, bug reports and corrections: contact page or a GitHub issue.
See also: Privacy & data protection · Terms of use · All 14 tools