Windows preparation and recovery
JSON Formatter / Validator
Paste JSON and get instant formatting with line-accurate error reports
🔒 See this tool’s privacy notes for local processing and external service details. Site analytics are described in our privacy policy.
Quick guide
What can JSON Formatter help you do?
Free online JSON formatter, minifier, and validator. Error line-number locator, tree view, one-click copy. Runs in browser — your JSON never uploaded.
Best for
Debug an API response, inspect a config file, or expand one-line JSON. Comments, trailing commas, undefined, and NaN are invalid JSON.
How to use it
Paste into Input JSON, then choose Format, Minify, or Validate Only. Indent offers 2 spaces, 4 spaces, or Tab; Sample loads test data.
How to read the result
Shows validity, characters, and keys. Parser positions map to line and column, but unsafe integers may lose precision.
Privacy and limits
Parsing stays in your browser. Never paste production API keys, access tokens, customer records, or raw personal data.
Formatting changes whitespace and unsafe integers. Keep original bytes for signatures and hashes.
Frequently Asked Questions
How do I find a JSON syntax error?
This tool reports the exact line and position, like "Unexpected token at line 5, position 12", and highlights the line.
Can I minify JSON?
Yes — the "Minify" button compresses multi-line JSON to one line for API payloads or database storage.
Is there a one-click copy?
Yes — the copy button at the top-right of the output box copies the formatted JSON to your clipboard.
Does this tool store my JSON?
No. Processing stays in your browser, but do not paste production API keys, access tokens, unredacted personal data, or customer records.
What's the max JSON size?
Theoretically unlimited (browser memory permitting). 10 MB or less is fast in testing.