Format Messy JSON from API Responses
Instantly pretty-print and validate JSON from API responses. Fix formatting, spot errors, and navigate complex structures.
The Problem
API responses come as minified, single-line JSON that's impossible to read. You need to inspect the structure, find a specific field, or validate the response — but it's one giant wall of text.
Why This Matters
Readable JSON is essential for debugging APIs, understanding data structures, and writing correct data access code. Pretty-printed JSON with proper indentation makes it instantly clear how objects nest, what fields exist, and where errors are. This is one of the most-used developer tools for a reason.
Step-by-Step Instructions
Paste your minified JSON
Copy the raw API response from your browser DevTools Network tab, curl output, or Postman. Paste the entire string including curly braces.
Click Format (Pretty)
The formatter adds proper indentation (2 spaces), line breaks, and sorts nothing — preserving the original structure. Syntax errors are highlighted immediately.
Validate and navigate
If your JSON is invalid, the error message shows exactly which line and character caused the issue. Fix it, then re-format.
Minify for production
Use the Minify button to compress formatted JSON back to a single line — useful when you need to embed JSON in environment variables or API requests.
Try It Now — JSON Formatter
Open full page →All processing happens in your browser — no data is sent to any server.
Before & After Example
{"user":{"id":123,"email":"[email protected]","profile":{"name":"Alice Johnson","role":"admin","permissions":["read","write","delete"],"created_at":"2026-01-15T10:30:00Z"},"subscription":{"plan":"pro","status":"active","mrr":49}}}
{
"user": {
"id": 123,
"email": "[email protected]",
"profile": {
"name": "Alice Johnson",
"role": "admin",
"permissions": ["read", "write", "delete"],
"created_at": "2026-01-15T10:30:00Z"
},
"subscription": {
"plan": "pro",
"status": "active",
"mrr": 49
}
}
}
Frequently Asked Questions
What's the difference between Format and Minify?
Format adds indentation and line breaks for readability. Minify removes all whitespace to reduce file size. Use Format for debugging, Minify for production.
Why does my JSON fail validation?
Common issues: trailing commas (not valid in JSON), single quotes instead of double quotes, unquoted keys, or missing commas between items.
Is my data sent to a server?
No. All formatting happens in your browser using JavaScript. Your JSON data never leaves your device.
Related Workflows
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