JSON Formatter

Format, minify, and validate JSON. For API development and debugging.

▶About this tool

This tool formats, minifies, and validates JSON in one click. Three features: 1) Format with indentation for readability, 2) Minify to one line to reduce transfer size, 3) Detect and display syntax errors. Ideal for API response inspection and debugging. All processing runs in the browser—no data sent to servers.

Tool interface 

 
   
 
 
 
Usage
 
     
  1. Paste JSON into the input field (API response or log copy works)
  2. Click Format for indented output—auto-copied to clipboard
  3. Click Minify for single line. Syntax errors shown in red.
    4.  
 
 
 
When to use
 
Checking API responses, editing config files, making logs readable, preparing data for transfer.
 
 
 
Examples
 
{"name":"test","items":[1,2,3]} → Format for indent, Minify for one line.
 
 
 
Tips
 
     
  • Data stays in browser. No server upload. Safe for sensitive data.
  • Ideal for pasting API responses to inspect structure.
  • Minified JSON reduces transfer size but loses readability.
    •  
 
 
 
FAQ
 
 
 
API response is one long line—how do I make it readable?
 
Paste the JSON into this tool and click Format. Indentation makes nesting visible and structure easy to inspect. Output is auto-copied so you can paste it into your editor.
 
 
When to use JSON vs YAML?
 
| Use case | Recommended | Reason |
| \| API / data exchange \| JSON \| Industry standard | fast parse \| |
| --- | --- |
| \| Config files (docker-compose) \| YAML \| Comments allowed | human-readable \| |
| CI/CD (GitHub Actions) | YAML | Indentation = structure |
This tool converts between them.
 
 
What are common JSON syntax errors?
 
Trailing comma, missing quotes on keys/strings, comments (JSON has no comments), leading zeros in numbers (e.g. 09).
 
 
What is JSON formatting?
 
Adding indentation for readability. Formatting makes nesting visible; minifying compresses to one line for smaller transfer size.
 
 
What does JSON stand for?
 
JavaScript Object Notation. Derived from JS object syntax but now a universal data format supported by many languages.
 
 
Is trailing comma an error in JSON?
 
Yes. No comma after the last element. JavaScript allows it, but JSON is strict.
 
 
Unexpected token JSON error
 
Indicates syntax error location. Check trailing comma, missing quotes on keys, duplicate or missing commas. This tool highlights the error when you format.
 
 
JSON.parse error how to fix
 
1) Remove trailing commas 2) Wrap keys in double quotes 3) Remove comments (// or /*) — JSON has no comments 4) Use this tool to format and locate the error.
 
 
 
 
 
Related tools
  
 
 
 
 
 
JSON & Data Format Set
  
 
Encode & Convert Set