JSON Formatter & Validator Online — Free, Private
Output
Paste any JSON into the input box, then click Format to beautify it or Minify to compact it. Validation happens live as you type — errors are shown immediately with the position of the problem, so you can fix malformed JSON without leaving the page.
How it works
- 1 Paste your JSON into the input Click the input pane and paste your raw JSON. The validator checks it in real time and highlights any syntax errors before you even click a button.
- 2 Click Format or Minify Hit Format to get pretty-printed JSON with 2-space indentation, or Minify to strip all whitespace for the smallest possible payload.
- 3 Copy the result Click Copy output to copy the formatted or minified JSON to your clipboard in one click.
Your data stays private
All processing happens entirely in your browser. No files, text, or data are ever sent to our servers. You can disconnect from the internet and this tool will still work.
Frequently asked questions
- How does the JSON formatter work?
- Paste JSON into the input box. The formatter uses the browser's native JSON.parse API to validate and parse your input, then JSON.stringify to re-serialize it — all in your browser, with no server calls.
- Is it free?
- Yes, completely free. No signup, no usage limits, no ads inside the tool.
- Does it validate JSON?
- Yes. Invalid JSON is detected immediately as you type. The status bar shows a descriptive error message including the position of the syntax problem.
- Can I minify JSON?
- Yes. Click the Minify button to remove all unnecessary whitespace and produce the smallest possible JSON string.
- Is my data private?
- Your JSON never leaves your device. All parsing and formatting happens in JavaScript inside your browser tab. No network requests are made.
- What is the maximum file size?
- There is no enforced limit. However, very large JSON objects (over 10 MB) may be slow to format due to browser memory constraints.