JSON Formatter & Validator
Pretty-print, validate, or minify JSON — instantly in your browser.
No upload No signup Works in browser Free
How to use
- 1Paste your JSON into the box.
- 2Click "Format" to pretty-print or "Minify" to compress.
- 3If the JSON is invalid, the error message tells you why.
JSON Formatter & Validator — why it works this way
Malformed JSON is a common source of debugging headaches. This tool parses and re-serializes your JSON locally using the browser's native JSON parser, so you get instant, accurate error messages without sending any data to a server.
Is my file uploaded? No. Everything happens locally in your browser using the Canvas/File APIs — your file is never sent anywhere.
FAQs
Is my JSON sent anywhere?+
No. Formatting and validation happen entirely in your browser.
What happens if my JSON is invalid?+
You'll see a clear error message describing what's wrong.