JSON Formatter
Format, validate, and analyze JSON with professional tools and insights.
Input & Settings
Output
Formatted JSON will appear here
Analysis & Stats
JSON statistics will appear here
JSON Formatting Examples
Unformatted Input
{"name":"John","age":30,"city":"New York"}Pretty Output
{
"name": "John",
"age": 30,
"city": "New York"
}Additional Examples
Formatting Minified JSON
Input:
{"name":"Alice","age":30,"city":"New York"}
Output:
{
"name": "Alice",
"age": 30,
"city": "New York"
}Converts a compact, single-line JSON string into a human-readable format with indentation.
Validating and Formatting Complex JSON
Input:
[ { "id": 1, "items": [ "apple", "banana" ] }, { "id": 2, "active": true, "config": null } ]
Output:
[
{
"id": 1,
"items": [
"apple",
"banana"
]
},
{
"id": 2,
"active": true,
"config": null
}
]Formats nested arrays and objects with consistent indentation, handling different data types (number, string, boolean, null).
Detecting Syntax Errors
Input:
{
"name": "Bob",
"age": 40 // Missing comma
"isStudent": false
}The tool will identify the missing comma after the 'age' field and report a validation error.
Examples
Beautify minified JSON
{"user":{"id":42,"name":"Ada","roles":["admin","editor"]},"active":true}{
"user": {
"id": 42,
"name": "Ada",
"roles": [
"admin",
"editor"
]
},
"active": true
}A compact, single-line API response reformatted with consistent 2-space indentation.
Minify for transport
{
"name": "webhook",
"url": "https://example.com/hook"
}{"name":"webhook","url":"https://example.com/hook"}Strips all whitespace to produce the smallest valid payload for shipping over the wire.
Invalid JSON is caught, not silently accepted
{
"id": 1,
"name": "Ada", // comments are not valid JSON
"active": true,
}JSON forbids comments and trailing commas — the validator pinpoints the offending line so you fix the real problem instead of chasing a generic parse failure downstream.
About this tool
JSON is the lingua franca of APIs and config files, but minified or hand-edited JSON is painful to read and easy to break with a single misplaced comma or bracket. This formatter validates your JSON and re-indents it with consistent spacing and line breaks so nested structures become instantly scannable — and when the syntax is invalid, it points you at the problem instead of failing silently.
Beyond pretty-printing, it offers minification for shipping compact payloads, search across large documents, useful statistics (key counts, depth, size), and file upload for working with big responses. Everything runs client-side — your data never leaves the browser — so it's safe to format sensitive API responses and configuration.
How to use
Paste your JSON
Paste JSON into the input area, or upload a .json file.
Format or minify
Click Format to indent and beautify, or Minify to collapse it to a single compact line.
Fix any errors
If the JSON is invalid, the validator reports the syntax error (e.g. a missing comma or bracket) so you can correct it.
Copy or download
Copy the formatted output or download it for reuse.
Use cases
Debugging API responses
Paste a raw API response and instantly read nested objects instead of squinting at a minified blob.
Editing config files
Format a .json config so you can edit it safely, then minify it back before deploying.
Reviewing large payloads
Search across and inspect the depth and size of big documents you'd otherwise struggle to navigate.
Validating hand-written JSON
Catch a missing comma or quote before your app or CI pipeline rejects the file.
What the formatter handles
| Feature | What it does |
|---|---|
| Validation | Catches missing commas, brackets, quotes and trailing characters |
| Pretty-print | Re-indents with consistent spacing for readability |
| Minify | Strips whitespace to produce the smallest valid payload |
| Statistics | Reports key count, nesting depth and document size |
| File upload | Loads large JSON files without pasting |
All processing is client-side — your JSON never leaves the browser.
Common mistakes
Mistake:Using single quotes around strings or keys.
Fix:JSON requires double quotes — "key" and "value", never 'key'.
Mistake:Leaving a trailing comma after the last item.
Fix:Remove the trailing comma; JSON forbids it, unlike JavaScript object literals.
Mistake:Adding // or /* */ comments.
Fix:JSON has no comments. If you need notes, keep them outside the file or switch to JSONC/JSON5 deliberately.
Mistake:Trusting formatted JSON without schema validation.
Fix:Formatting proves the syntax is valid, not that the shape matches your contract — validate types separately.
Frequently asked questions
Related guides
JSON Formatting and Validation: Best Practices
Why strict JSON breaks so easily, the syntax errors that cause most failures, and the formatting habits that make JSON readable in diffs and reviews — with validation, minifying, and search tips.
Converting CSV to JSON: A Practical Guide
How to turn spreadsheet-style CSV into structured JSON — header handling, quoting and escaping rules, delimiter variants, type conversion gotchas, and how to go the other way.
Best Free Developer Tools in 2026: An Honest Comparison
The best free, browser-based developer tools compared — CyberChef, Regex101, JWT.io, and the privacy-first alternatives. What to use for JSON, regex, JWTs, hashing, UUIDs, and more.
JSONPath: A Practical Guide to Querying JSON
How to use JSONPath expressions to extract values from nested JSON — dot notation, wildcards, recursive descent, and filter expressions, with copy-paste examples.
References & standards
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