JSON Formatter Online - Format and Validate JSON in Your Browser

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JSON Minifier

Minify JSON by removing whitespace and line breaks. Validate JSON and copy compact output.

JSON Schema Validator

Validate JSON data against common JSON Schema rules with readable path-level error reports.

JSON Path Tester

Test JSON paths against JSON data. Query nested objects, arrays, indexes, and wildcard matches.

Example

Beautify a compact API response

Formatting makes nested objects and arrays easier to scan when you are debugging an API response.

Input


                        {"user":{"id":42,"name":"Alex"},"roles":["admin","editor"],"active":true}

Output


                        {
  "user": {
    "id": 42,
    "name": "Alex"
  },
  "roles": [
    "admin",
    "editor"
  ],
  "active": true
}

Catch a trailing comma before a deploy

JavaScript object literals often allow trailing commas, but strict JSON does not. Validate config snippets before copying them into tools that expect JSON.

Input


                        {
  "name": "QuickToolFlow",
  "enabled": true,
}

Output


                        Invalid JSON: unexpected token near the trailing comma

Minify a small JSON fixture

Minified JSON is useful for compact examples, URLs, test fixtures, and storage where human readability is not required.

Input


                        {
  "event": "signup",
  "source": "landing-page",
  "paid": false
}

Output


                        {"event":"signup","source":"landing-page","paid":false}

Validate an API response before testing

API clients and test runners expect the response body, not copied headers or log prefixes. Clean the payload before writing assertions.

Input


                        HTTP 200 OK
{"id":"42","active":"false","roles":["admin"]}

Output


                        Remove the HTTP status line first, then validate and format the JSON body.

Practical Notes

JSON does not allow trailing commas, comments, or unquoted object keys. Those are common reasons validation fails.
This tool parses JSON with the browser JavaScript engine, so the result follows standard JSON.parse behavior.
Formatting changes whitespace only. It does not change key names, values, array order, or object structure.
If a payload is valid JSON but still breaks your app, validate it against a schema to catch missing fields or wrong value types.
When debugging copied API responses, first remove log prefixes, HTTP headers, or text around the JSON object before validating.
Before API testing, check syntax first, then inspect field types and array shapes. A payload can be valid JSON but still violate the API contract.

How to Use

1. Paste raw JSON, an API response, or a configuration snippet into the input field.
2. Choose Format / Beautify to make it readable, Minify to compact it, or Validate to check syntax only.
3. Read the status message if the JSON parser finds an error.
4. Copy the formatted or minified result when the output looks right.

Features

Formats nested JSON with consistent two-space indentation
Validates JSON before formatting or minifying
Shows parser errors without sending data to a server
Minifies JSON for compact API payloads or configuration files
Works with pasted API responses, config snippets, and local test data
Runs entirely in your browser for private JSON inspection
Supports API testing workflows before schema or contract validation

Use Cases

Inspecting API responses while debugging frontend or backend code
Cleaning compact JSON before sharing it in tickets or documentation
Checking configuration files before committing them
Minifying JSON payloads for examples, tests, or storage
Comparing raw webhook payloads before writing parsing logic
Preparing readable JSON fixtures for unit tests and bug reports
Validating copied API responses before adding assertions in Postman, Playwright, Cypress, or unit tests

Frequently Asked Questions

Why does my JSON fail validation?

The most common causes are trailing commas, comments, single-quoted strings, unquoted keys, or missing closing brackets. JSON is stricter than JavaScript object syntax.

Does formatting JSON change the data?

No. Formatting only changes whitespace and indentation. The object keys, values, arrays, and nesting remain the same after parsing.

Can I paste private API responses here?

The formatter runs in your browser, so pasted JSON is processed locally. Still, avoid sharing sensitive data in screenshots, browser extensions, or copied outputs.

Is this JSON formatter online or local?

The page is loaded online, but formatting and validation run locally in your browser after it loads. Your pasted JSON is not sent to QuickToolFlow for processing.

What is the difference between format and minify?

Format adds indentation and line breaks for readability. Minify removes unnecessary whitespace to make JSON shorter.

Can this fix invalid JSON automatically?

No. It reports parser errors so you can fix the source intentionally. Automatic repair can hide problems such as missing quotes, truncated arrays, or non-JSON JavaScript syntax.

Why is my API response valid but my app still rejects it?

Syntax validation only proves the text is parseable JSON. Your app may also require certain fields, value types, enum values, or array shapes. Use schema validation for those checks.

Should I validate JSON before API testing?

Yes. Validate syntax first so parser errors do not hide real API problems. After the JSON is parseable, inspect field types, required keys, arrays, and schema rules before writing assertions.