JSON Formatter & Validator
Format, validate, and minify JSON in your browser. Inspect error locations, copy the result, or download a JSON file.
Input JSON
💡 Tips:
- Use "Format" to beautify minified JSON for better readability
- Use "Minify" to compress JSON before sending over network
- Click Format or Minify to validate; use the error link to select a reported problem character
- All processing happens in your browser - your data stays private
Practical guide
Inspect an API response
Use formatting to inspect nested API data; use minification when you need compact JSON. Neither operation validates an API schema or checks whether the values are correct for your application.
Worked example
Paste {"order":{"id":42,"items":["pen","notebook"]}} and click Format. The order object and items array appear on separate indented lines. Minify returns the compact structure. A trailing comma, as in {"id":42,}, is invalid JSON: remove the comma rather than changing the value.
Check the result
Compare the keys and values before copying the result. JSON keys and string values require double quotes; comments and JavaScript expressions are not accepted. When an error position is available, use the selection link to inspect it.
Limitations to know
This uses JavaScript JSON parsing. Integers outside the safe range (±9,007,199,254,740,991) can lose precision, and duplicate keys retain only their last value. Keep large identifiers as strings. Formatting happens in a background worker; very large inputs still need device memory.
How to Use
Follow these simple steps for quick results
- 1Paste your JSON data into the input field
- 2Click Format or Minify to validate and detect syntax errors
- 3Click "Format" to beautify and add proper indentation
- 4Use "Minify" to compress JSON and remove whitespace
- 5Copy the formatted result to your clipboard
- 6Download as a .json file if needed
Key Features
✨ Instant validation with error detection
🎨 Indented plain-text output for readability
📏 Auto-format with proper indentation
🗜️ Minify to reduce file size
📋 One-click copy to clipboard
📥 Download formatted JSON
🔒 100% client-side processing
⚡ Fast processing for large files
Frequently Asked Questions
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data-interchange format that is easy for humans to read and write, and easy for machines to parse and generate. It is widely used for data exchange between web servers and clients.
How do I validate JSON?
Paste your JSON and click Format or Minify. If parsing fails, the tool displays the parser error and a line and column when the browser provides a position. Use the error link to select the problem character.
What does JSON formatting do?
JSON formatting (also called beautifying or pretty-printing) adds proper indentation and line breaks to make JSON data more readable. It is especially helpful when working with minified or compressed JSON.
Can I minify JSON?
Yes! Our tool includes a minify option that removes all unnecessary whitespace and line breaks, reducing file size. This is useful when you need to send JSON data over a network.
Is my JSON data safe?
Absolutely. All JSON processing happens entirely in your browser using JavaScript. No data is sent to any server, ensuring complete privacy and security for your sensitive data.
What are common JSON errors?
Common errors include: missing or extra commas, unquoted keys, single quotes instead of double quotes, trailing commas, and mismatched brackets or braces. Our validator will point out these issues.
Can I format large JSON files?
Yes, our tool can handle large JSON files efficiently. However, very large files (>10MB) may take a moment to process depending on your device performance.