JSON Formatter, Validator & Minifier
Paste JSON. Get formatted, minified, or validation errors instantly. Everything runs in your browser — no payload is ever sent anywhere.
Invalid JSON
What this does
Three modes:
- Format — re-renders your JSON with 2-space indentation, sorted properties optional. Catches syntax errors as you type.
- Minify — strips whitespace, returns compact valid JSON. Useful for embedding in URLs or reducing payload size.
- Validate — happens automatically; the status pill above turns red on parse error and shows the column number where the parser choked.
Privacy
Your JSON never leaves your browser. The formatter uses the standard JavaScript JSON.parse + JSON.stringify — both run locally. No network requests, no logging. Verify in your browser's network tab.
FAQ
Why is my JSON failing to parse?
Most common: trailing commas (not allowed in strict JSON), single quotes (must be double), unquoted keys, or comments (also not allowed in JSON). The error message above shows the column number.
Can I paste very large JSON?
Yes — anything your browser can hold in memory. Tested up to ~50MB. Larger than that may cause UI lag while parsing.
Is this safe for confidential data?
All processing is client-side; no data is sent to a server. The input persists in your browser's localStorage between visits — clear it manually if you need to.
No tracking, no signup. All math runs locally in your browser.