About JSONfree
JSONfree (json3.com) is a collection of JSON tools that run locally in your browser. We bring the JSON operations developers use every day into one clean, fast, trustworthy site — and everything is processed locally in your browser.
What we solve
Developers work with JSON every day: formatting, validating, converting, diffing, generating test data. These used to be scattered across many tools, some of which upload your data to a server. JSONfree brings them together in one place — and keeps your data inside your browser.
Principles
Local · no upload: all computation happens in your browser; inputs and results never reach a server. Free · no ads: every feature is free, with no popups and no tracking. Ready to use: no signup, no install, works offline.
The toolset
Eight categories, 30+ tools: core workbench (format / validate / minify / repair / tree view), view & compare (viewer / large JSON / diff), visualization (table / node graph), conversion (CSV / XML / YAML / Excel / SQL), code generation (TypeScript / Go / Python / Java / Rust / C#), Schema (validate / generate), query & decode (JSONPath / jq / JWT), and data generation (Mock / Base64 / URL / timestamp / UUID / Hash / regex).
Privacy & security
We treat privacy as a core feature, not an add-on. See the Privacy Policy for details — in short, your data is processed in your own browser and is never uploaded or stored.
Technology
The Site is built as a pure static site with modern front-end technology; all tools run on the client, so it is fast, works offline, and leaves no data on the server.