Developer Tools
JSON Formatter & Validator
Pretty-print, minify, and validate JSON. 100% in your browser. Pinpoints the exact line of any error.
Input
Output (formatted)
A faster JSON tool
Paste any JSON — API response, config file, log entry — and we instantly format, validate, and surface errors. Choose your indent (2 spaces, 4 spaces, tabs) or minify for production. Sort keys alphabetically for cleaner diffs.
All processing happens client-side. We never see your data. No API rate limits, no account, no upload size limit.
Frequently Asked Questions
How does the JSON formatter work?▾
We use the browser's built-in JSON.parse() to validate, then JSON.stringify() to re-format with your chosen indent. If parsing fails, we surface the exact line, column, and character position of the error.
Is my JSON sent to a server?▾
No. Everything happens in your browser. Your JSON never leaves your device, so it's safe to paste sensitive data, API responses with credentials, etc.
What's the difference between formatting and minifying?▾
Formatting (pretty-print) adds indentation and line breaks for human readability. Minifying strips all whitespace to make the JSON as small as possible — useful for production payloads where bytes matter.
Can it handle JSON5 or JSONC?▾
Currently we only handle strict JSON (RFC 8259). Comments, trailing commas, and unquoted keys (JSON5/JSONC features) are not supported. If you need those, run your input through a JSON5 parser first.
Why am I getting a parse error?▾
Common causes: trailing comma after the last item in an array/object, single quotes instead of double, unquoted property names, missing closing bracket. We point at the exact position so you can find it fast.