Paste JSON to beautify, minify, or validate. Instant formatting.
JSON (JavaScript Object Notation) is the most widely used data interchange format on the web. It is used in REST APIs, configuration files, databases (MongoDB, Firebase), and package managers (package.json).
| Type | Example | Notes |
|---|---|---|
| String | "hello world" | Must use double quotes |
| Number | 42, 3.14, -1 | No quotes, no leading zeros |
| Boolean | true, false | Lowercase only |
| Null | null | Represents empty value |
| Array | [1, 2, 3] | Ordered list of values |
| Object | {"key": "value"} | Unordered key-value pairs |
| Error | Wrong | Correct |
|---|---|---|
| Single quotes | {'key': 'val'} | {"key": "val"} |
| Trailing comma | {"a":1, "b":2,} | {"a":1, "b":2} |
| Unquoted keys | {key: "val"} | {"key": "val"} |
| Single value | Hello | "Hello" or {"v":"Hello"} |
| Comments | {"a":1 // note} | Not allowed in JSON |
| Factor | JSON | XML | YAML |
|---|---|---|---|
| Readability | Good | Verbose | Best |
| File size | Small | Large (tags) | Small |
| Comments | No | Yes | Yes |
| API standard | Dominant | Legacy | Rare |
| Config files | Common | Rare now | Dominant |
| Parsing speed | Fast | Slow | Moderate |
It takes raw or minified JSON and formats it with proper indentation, detects syntax errors, and makes it human-readable. It runs entirely in your browser — no data is sent to any server.
The most common causes: single quotes instead of double quotes, trailing commas after the last item, unquoted property names, or missing brackets/braces. Use this tool to highlight exact error locations.
JSON itself has no size limit. This tool can handle files up to 10MB in-browser. For larger files, use command-line tools like jq. Most APIs limit JSON payloads to 1-10MB.
No. JSON only supports strings, numbers, booleans, null, arrays, and objects. Dates are typically stored as ISO 8601 strings (e.g., "2026-03-25T10:30:00Z") and parsed by the application.
Yes. All formatting happens locally in your browser using JavaScript. No data is transmitted to any server. Your JSON content remains 100% private.
Professional-grade json formatter tool designed for accuracy and privacy. Calcora provides expert-built utilities entirely free of charge with zero data collection.
All calculations happen instantly and locally within your browser, ensuring your data remains absolutely private.
No. Calcora tools run 100% client-side. No data is uploaded or stored on any external server.
Yes, all tools on Calcora are completely free to use without any account or subscription.