JSON Formatter & Validator
Pretty-print or minify JSON data with syntax validation.
About This Tool
JSON Formatter is a free online tool that pretty-prints raw or minified JSON into a human-readable format with proper indentation, and minifies formatted JSON back into a compact single line. It validates your JSON in real time, showing the exact position of any syntax error. Choose from 2-space, 4-space, or tab indentation to match any code style.
All processing runs instantly in your browser using JSON.parse and JSON.stringify — no server involved, no data retention. The formatter handles nested objects and arrays of any depth, making it equally useful for small configuration snippets and large API response payloads. Error messages from the JSON parser are surfaced directly to help you locate and fix syntax issues.
JSON Formatter is used daily by developers inspecting API responses, debugging configuration files, validating JSON schemas, and preparing minified JSON for deployment. It is a simple, indispensable tool for any developer who works with REST APIs, web services, or JSON-based configuration formats.
How to Use
- 1
Paste your JSON into the input field.
- 2
Click Format to pretty-print the JSON, or Minify to compress it into a single line.
- 3
Copy the formatted output with the copy button.
- 4
Choose 2-space, 4-space, or tab indentation to match your project's code style.
- 5
Use the minified output in production code or API payloads where whitespace should be minimal.
Features
Pretty-Print & Minify
Format JSON for readability with custom indentation, or minify it to remove all whitespace.
Syntax Validation
Invalid JSON is detected and an error message with the exact position is shown.
Custom Indentation
Choose 2 spaces, 4 spaces, or tab indentation to match your project's code style.
Instant Processing
JSON is formatted or minified instantly in your browser with no server required.
Common use cases
- ›Format raw API responses from Postman, curl, or browser DevTools into readable JSON.
- ›Validate JSON configuration files and find syntax errors before deployment.
- ›Minify JSON for production API payloads or localStorage values to reduce size.
- ›Debug complex nested JSON objects from webhooks, SDKs, or third-party services.
Read our guide
JSON Formatter & Validator — Complete Guide →FAQ
Can it validate JSON?
Yes, invalid JSON will show an error message with the position of the syntax error.
What indentation options are available?
2 spaces, 4 spaces, or minified (no whitespace).
What common JSON errors does it detect?
Trailing commas, missing closing brackets or braces, unquoted keys, single-quoted strings, and other syntax violations that make JSON invalid.
Can I format JSON from an API response?
Yes. Copy the raw JSON from your browser's network tab, an API client like Postman, or a terminal response, paste it in, and click Format to get a readable version.
What is the difference between Format and Minify?
Format (pretty-print) adds indentation and newlines to make JSON human-readable. Minify removes all unnecessary whitespace to produce the smallest possible JSON string, suitable for network transmission or storage.