Developer tool

JSON Formatter & Validator Online

Pretty print, validate and minify JSON, inspect nested data, and review syntax errors in your browser.

Presets:
Indentation:
Input Raw JSON 0 chars | 0 lines 
// Formatted JSON output will appear here...
// Interactive tree view will render here...
Target Format: 
// Converted schema format will appear here...
Formatted Size 0 B
Minified Size 0 B
Compression Savings 0%
Total Keys 0
Max Depth 0
Node Types Objects: 0 | Arrays: 0 | Primitives: 0

How to use this tool

  1. Paste a JSON object or array, or load the sample in the input editor.
  2. Choose Format or Minify, then review validation feedback before copying the result.
  3. Use Tree View to inspect nested values and download the checked JSON.

Example and use case

{"orderId":"A-104","items":[{"sku":"PEN","quantity":2}],"paid":false}

Limitations to check

Formatting confirms syntax, not business rules or JSON Schema compliance. Review repairs before use: they can change the meaning of malformed input. Loading JSON from a URL makes a request to that host and depends on its CORS policy.

Processing and privacy

The tool's browser code handles entered text or selected files locally. Optional URL imports and external resources can make network requests. This website also uses third-party scripts, including analytics and advertising. Read the privacy policy and use sample data when testing sensitive workflows.

Found a problem? Report a tool issue with the browser version and steps to reproduce it. Avoid sending private document content or credentials.

Frequently asked questions

How do I fix invalid JSON?

Use double quotes around keys and strings, lowercase true/false/null, and remove comments and trailing commas. Validate again after each correction.

Does pretty printing change JSON values?

Formatting changes whitespace. Check the result when using repair or conversion features because those operations can alter values or structure.

Is pasted JSON uploaded?

Pasted JSON is parsed in the browser. The optional URL loader contacts the URL you enter; avoid putting secrets in a remote URL.

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