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Hazuu Tools

JSON Formatter & Beautifier

Validate, format, and minify your JSON data instantly in a secure, client-side environment.

Input JSON
Output
Formatted output will appear here...
info

About JSON Formatter

JSON Formatter is a free online tool that takes raw or minified JSON text and reformats it with consistent indentation, line breaks, and key ordering so it is easy for humans to read and review. Paste any JSON string — whether it came from an API response, a config file, or a database export — click Format, and the output pane instantly shows a cleanly structured document you can inspect, copy, or share.

Developers reach for this tool when working through API integrations where the response payload arrives as a single compressed line, when debugging a configuration file that has drifted into an unreadable state, or when reviewing a colleague's data fixture in a pull request. The minify function works the opposite way: it collapses formatted JSON into the smallest possible string, which is useful before embedding a payload in a curl command, a URL parameter, or an environment variable. Three indentation styles — 2 spaces, 4 spaces, and tab — let you match the code style of the project you are pasting into.

All processing runs entirely inside your browser using the native JavaScript JSON.parse and JSON.stringify APIs. Your data is never uploaded, stored, or transmitted to any server. That means API keys, tokens, personally identifiable information, and internal configuration values stay on your own machine. The tool is free with no account required and no usage limits.

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Key Features

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Format and minify in one place

Two distinct operations — beautify with indentation or compress to a single line — are available from the same toolbar, so you never need to switch tools mid-task.

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Configurable indentation

Choose 2-space, 4-space, or tab indentation before formatting so the output matches your project's style guide or linter settings.

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Inline validation with error messages

If your JSON contains a syntax error — an unquoted key, a trailing comma, or a mismatched bracket — the tool shows the exact parser error message and blocks output until the input is valid.

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100% client-side processing

Parsing and serialization happen in your browser using JavaScript's built-in JSON engine. Nothing leaves your machine, making it safe for API keys, tokens, and internal config data.

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Handles nested structures

Deeply nested objects, arrays of objects, mixed value types, and Unicode string values are all preserved faithfully — no data is altered during formatting.

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One-click copy

Copy the formatted or minified output to your clipboard with a single button click, ready to paste into your editor, terminal, or API client.

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How to Use

01

Paste Content

Copy your raw JSON string and paste it into the left editor pane.

02

Process

Click "Format" to beautify or "Minify" to compress the code.

03

Copy Result

Use the copy button to grab your formatted JSON for use.

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Example

A minified API response is reformatted with 2-space indentation so nested fields are immediately readable.

Minified JSON input
{"user":{"id":42,"name":"Alice","roles":["admin","editor"],"active":true}}
Formatted JSON output
{
  "user": {
    "id": 42,
    "name": "Alice",
    "roles": [
      "admin",
      "editor"
    ],
    "active": true
  }
}
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Common Use Cases

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    Inspecting API responses during development

    REST and GraphQL APIs typically return minified JSON. Paste the raw response body here to expand it into a readable structure before you start writing code against the fields.

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    Debugging malformed JSON configs

    Configuration files for Node.js, package managers, CI pipelines, and cloud services are valid JSON. When one of these files breaks a build, formatting it here instantly reveals the line with the syntax error.

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    Preparing payloads for curl or Postman

    Use the minify function to collapse a multi-line JSON body into a single-line string that you can embed in a -d flag, a URL parameter, or an environment variable without shell escaping issues.

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    Reviewing data fixtures in code reviews

    Test fixtures and mock data files are often checked in as formatted JSON. Re-format a colleague's fixture to a consistent indentation style before merging so diffs stay clean.

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    Validating JSON before sending to an API

    Paste a hand-written JSON payload to catch missing quotes, trailing commas, or bracket mismatches before the API rejects it with a 400 error — faster than reading a raw error response.

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Frequently Asked Questions

Is my data secure? expand_more
Yes, absolutely. All processing happens locally in your browser using JavaScript's native JSON.parse and JSON.stringify. No data is sent to any server, ensuring API keys, tokens, and private payloads remain on your machine.
Does it support large files? expand_more
Yes, the formatter handles files of any reasonable size. Very large inputs (50 MB or more) may be slow depending on your device, because the entire parse and stringify operation runs in the browser's main thread.
Can I validate JSON here? expand_more
Yes. If you paste invalid JSON — for example, an unquoted key, a trailing comma after the last element, or a missing closing bracket — the tool displays the exact syntax error from the JavaScript parser and shows no output until the issue is corrected.
Which indentation styles are available? expand_more
You can choose between 2 spaces, 4 spaces, or a tab character. Select the style that matches your project's .editorconfig or linter settings before clicking Format.
How is JSON Formatter different from XML Formatter? expand_more
JSON Formatter works exclusively with JSON syntax — curly-brace objects, arrays, strings, numbers, booleans, and null. XML Formatter handles angle-bracket markup with attributes, namespaces, and CDATA sections. The two formats are structurally different; a JSON formatter cannot parse XML and vice versa.
How is this different from YAML Formatter? expand_more
JSON and YAML are related but distinct formats. JSON uses strict quoted keys and explicit braces and brackets. YAML uses indentation-based structure and allows unquoted strings. This tool only processes valid JSON; it will report a syntax error if you paste YAML into it. Use the YAML Formatter for YAML files.
Does formatting change the data? expand_more
No. The formatter calls JSON.parse to read the data and JSON.stringify to re-serialize it. The output is semantically identical to the input — only whitespace and newlines are adjusted. Key order is preserved as the JavaScript engine parsed it.
What happens to comments in a JSON file? expand_more
Standard JSON does not support comments, and the tool uses the native JSON.parse API which follows the spec strictly. A file containing // or /* */ comments will be reported as invalid. If your file is actually JSONC (JSON with Comments) used by VS Code settings, remove the comments first or use a dedicated JSONC parser.