JSON Formatter & Validator
Minified or badly-indented JSON is hard to read and debug. This tool formats any valid JSON into clean, indented output and flags syntax errors with a clear message when the JSON is invalid.
How to Use This Tool
- Paste your raw or minified JSON into the input box.
- Choose your preferred indentation style.
- Click Format & Validate — valid JSON is beautified instantly, and errors are reported with a message.
Why Use ToolVigo's JSON Formatter
- Validates JSON syntax and reports the specific parsing error.
- Choice of 2-space, 4-space or tab indentation.
- Nothing leaves your browser — safe for sensitive API responses or config files.
Supported Formats
Any valid JSON: objects, arrays, strings, numbers, booleans and null, including deeply nested structures.
Privacy & Security
This tool runs entirely in your browser. Your input is never uploaded to ToolVigo's servers, and nothing is stored once you leave the page.
Frequently Asked Questions
Why does my JSON show as invalid when it looks correct?
Common causes are trailing commas, single quotes instead of double quotes, or unquoted keys — all valid in JavaScript object literals but not in strict JSON.
Is there a size limit?
No hard limit is enforced, but very large JSON payloads (multiple megabytes) may be slow to format in the browser.