Local-first • No server upload
Developer

JSON Formatter and Validator

Format, validate, and inspect JSON without uploading it. — 100% browser-side, no server upload, works offline.

Developer utility

Format and validate JSON

Local validation

Drop JSON files here

or choose files from your device

Drop a JSON file here or choose a file. You can also paste JSON below.

0 characters · files and pasted JSON stay local

Common questions

Does formatting change the data?

No. Formatting changes whitespace only when the input is valid JSON.

What happens on invalid JSON?

The tool shows a local error message and leaves your original input untouched.

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