How to Use the JSON Formatter & Validator
Paste or type your raw JSON into the input box on the left. The tool checks it in real time and instantly flags any syntax errors — missing commas, unclosed brackets, or trailing commas — showing you the exact line number so you can fix it fast. Once your JSON is valid, click "Format" to auto-indent it with proper spacing and syntax highlighting, making deeply nested objects and arrays easy to read. If you need a compact version for production code or an API payload, click "Minify" to strip out all whitespace and reduce file size. Use the copy button to grab the result instantly, or download it as a .json file. This tool runs entirely in your browser, so your data is never uploaded to a server — it's safe to paste API keys, config files, or sensitive payloads while debugging.
Frequently Asked Questions
What is JSON used for?
JSON (JavaScript Object Notation) is a lightweight format for storing and transporting data, frequently used when sending data from a server to a web page.
How do I format a JSON file?
You can use a JSON formatter tool to automatically indent nested objects and arrays, adding line breaks to make the data 'pretty-printed' and human-readable.
Why is my JSON invalid?
Common JSON syntax errors include missing quotation marks around keys, trailing commas at the end of arrays or objects, and mismatched brackets.
Is JSON better than XML?
Developers generally prefer JSON over XML because it is less verbose, faster to read and parse, and maps seamlessly to native data structures in modern programming languages.
Can JSON contain comments?
No, the official JSON standard does not support comments. Including comments will cause standard JSON parsers to throw a syntax error.
Related Tools
- Base64 Encoder/Decoder – Encode and decode Base64 strings instantly.
- CSS Minifier – Compress your CSS for faster page load times.
- Markdown to HTML – Convert Markdown to clean HTML code.
- Epoch Timestamp Converter – Convert between Unix timestamps and human dates.