JSON Formatter Online Free — Pretty Print & Validate JSON

Raw JSON from APIs is often minified — one long line that is hard to read and debug. Pretty-printing adds indentation so you can inspect nested objects, spot missing commas, and compare payloads before deployment.

How to format JSON online for free

• Paste JSON into the formatter — output updates live
• Use Format mode for readable indentation
• Switch to Minify for compact production payloads
• Validate mode confirms syntax without reformatting

When to pretty-print JSON

• Debugging REST or GraphQL API responses
• Reviewing config files before commit
• Validating JSON syntax before sending to production
• Sharing formatted output with teammates via shareable link

Common JSON errors

• Trailing comma after last array/object item
• Single quotes instead of double quotes
• Unescaped newlines inside strings
• Missing closing bracket or brace

What makes Utiliio different

• Live output — results update as you paste
• Error line and column when JSON is invalid
• Structure preview with object/array counts and max depth
• Format, Minify, and Validate modes on one page
• Share button encodes input in the URL for team handoffs