I built a free JSON formatter that never uploads your data — here's why that matters

Gokul Das — Wed, 04 Mar 2026 07:22:48 +0000

If you've ever pasted an API response with credentials or sensitive data into an online JSON formatter, you've probably uploaded that data to a third-party server without realizing it.

Most online JSON tools process data server-side. That means your JSON goes to their servers before coming back formatted.

I built JSONStudio (https://jsonstudio.online) differently — everything runs 100% in your browser using client-side JavaScript. Your data never leaves your device.

What it does
JSON Formatter — beautify and minify with custom indentation
JSON Viewer — explore in Tree, Table, Code, or Text view
JSON Validator — real-time error detection with exact line/column
JSON Diff — compare two JSON files side by side
20+ Converters — JSON → TypeScript, YAML, CSV, Java, Go, Kotlin, XML, GraphQL, Rust, Scala, Zod Schema, and more
Why client-side matters
When working with API responses, you often have:

Authentication tokens
User personal data
Internal API structure
Credentials in config JSONs
With client-side processing, none of that leaves your machine.

Tech stack
Built with Next.js (static export), deployed on a CDN. The output: 'export' config means there's no Node.js server involved at all — it's all static HTML + JS.

Try it at https://jsonstudio.online — feedback welcome!

DEV Community: Gokul Das

I built a free JSON formatter that never uploads your data — here's why that matters