A fast, private JSON toolkit

JsonLab is a free suite of browser-based JSON tools for developers. The editor above formats and validates JSON instantly as you type — and because everything runs in your browser, your data never leaves your device.

Format & beautify

Turn minified or messy JSON into clean, indented, readable output instantly. Pick 2-space, 4-space or tab indentation.

Validate as you type

Catch syntax errors immediately, with the exact line and column highlighted so you can fix them fast.

Explore as a tree

Collapse and expand deeply nested structures, search keys and values, and copy the JSONPath of any node.

Minify

Compress JSON to the smallest possible size for transport or storage with one click.

Private by default

No uploads, no accounts, no tracking without consent. Safe to use even with sensitive data.

Fast on large files

Built on a VSCode-grade editor that stays responsive even with big documents.

Explore the tools

JSON Formatter & Beautifier JSON Validator JSON to CSV Converter JSON Diff Tool

Frequently asked questions

Is JsonLab free?

Yes. JsonLab is completely free and supported by unobtrusive advertising that never appears inside the editor.

Is my JSON uploaded to a server?

No. All processing happens locally in your browser, so your JSON never leaves your device.

Do I need to create an account?

No account is required. Just open the editor and start working.

Does it work on mobile?

Yes — JsonLab is fully responsive and works in any modern browser on desktop or mobile.

JsonLab — online JSON formatter, beautifier, validator and tree viewer