JSON Formatter & Validator
Format, minify, and validate JSON instantly in your browser with zero server communication. Paste any minified or malformed JSON to pretty-print it with consistent indentation, compress it for API payloads, or catch syntax errors with exact error positions.
How to Use the JSON Formatter & Validator
- 1
Paste your JSON
Copy any JSON string — minified, formatted, or partially malformed — and paste it into the input area.
- 2
Choose an action
Click "Format" to pretty-print with 2-space indentation, or "Minify" to compress to a single line.
- 3
Review validation
If your JSON has syntax errors, an error message appears showing the exact position of the first problem.
- 4
Copy the output
Click the Copy button to copy the formatted or minified output to your clipboard.
Key Features
Fully Private
JSON never leaves your browser — safe for API tokens, credentials, and sensitive payloads.
Full Validation
Catches all RFC 8259 syntax violations including trailing commas, single quotes, and unquoted keys.
Instant Processing
Format or minify any size JSON in milliseconds using the browser's native JSON APIs.
Pro Tips
Use Ctrl+F inside the formatted output to search for specific keys or values in large JSON objects.
Minified JSON is ideal for environment variables and API request bodies where whitespace wastes bytes.
If validation fails, the error position points to the first syntax problem — fix that one and re-validate rather than scanning the whole file.
Privacy Note
All processing in this tool runs entirely in your browser — no data is transmitted to any server. Your input is never logged, stored, or shared. This tool is free to use with no account or registration required.
Frequently Asked Questions
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Your input is processed locally in your browser and is never stored, transmitted, or shared with any server. See our Privacy Policy.