Free Tool
JSON Formatter & Validator
Format, validate, and minify JSON instantly. Pretty-print with 2 or 4 space indentation or compress to a single line — all in your browser, no sign-up needed.
JSON Formatter & Validator
Indent:
What is a JSON formatter?
Pretty-printing JSON adds consistent indentation and line breaks, making nested structures easy to read. Minifying removes all whitespace to reduce payload size.
Validation
This tool validates your JSON as you type. Common errors include trailing commas (not allowed in JSON), single-quoted strings (must be double-quoted), and unquoted object keys.
Developer use cases
JSON formatting is useful when inspecting API responses, reading config files, comparing payloads, and reviewing log output that was minified for transmission.
How to use
- Paste your JSON into the input area.
- Click "Format" to pretty-print with indentation, or "Minify" to compress it. Validation errors appear inline with the line number.
- Click "Copy" to copy the formatted result to your clipboard.
Examples
- Simple: Paste
{"name":"Alice","age":30}and click Format → each key-value pair is on its own indented line, making the structure immediately readable. - Developer workflow: An API returns a minified 2 KB response. Paste it here, click Format, then scan for the specific field you need — far faster than reading a single-line blob.
- Edge case: Trailing commas are valid in JavaScript objects but not in JSON. If you paste a JS object literal, the validator will report a syntax error. Remove trailing commas before formatting.
Your JSON stays in your browser — no data is sent to any server.
Frequently Asked Questions
- What is JSON formatting?
- JSON formatting (pretty-printing) adds consistent indentation and line breaks to a compact JSON string, making it human-readable. A JSON formatter takes raw or minified JSON and restructures it for easy reading and debugging.
- What is JSON minification?
- JSON minification removes all unnecessary whitespace, newlines, and indentation from a JSON document, producing the smallest possible valid JSON string. This reduces file size for transmission over networks.
- How do I validate JSON?
- Paste your JSON into this tool and click "Validate Only". It parses your JSON and reports whether it is valid. If there are syntax errors, the exact error message is shown to help you fix them.
- Is this JSON formatter free?
- Yes, completely free with no sign-up required. All processing happens in your browser — no data is sent to any server.