QQudo Tools

JSON Formatter & Validator

Beautify, indent, validate and compress JSON data. Detect syntax errors with line and column information. All JSON data is processed locally in your browser.

Indent

Example

Format
{"name":"Qudo","tools":["JSON","Text"],"active":true}
Format
{
  "name": "Qudo",
  "tools": [
    "JSON",
    "Text"
  ],
  "active": true
}
Compress
{"name":"Qudo","tools":["JSON","Text"],"active":true}

About This Tool

The online JSON formatter and validator helps you beautify, indent, validate and compress JSON data. The tool can detect common syntax errors and display the line and column where the error occurs. All JSON data is processed locally in your browser and will not be uploaded to any server.

How to Use

  1. 1Paste JSON data into the input box, or upload a .json file.
  2. 2Choose 2 spaces, 4 spaces, or Tab for indentation.
  3. 3Click "Format" to beautify the JSON structure.
  4. 4If there are errors, fix the corresponding lines based on the prompts.
  5. 5Click "Copy" or download the processed JSON file.
  6. 6To reduce file size, click "Compress JSON".

Processing Rules

Formatting

Adds line breaks and indentation based on object and array nesting levels.

Validation

Parses input according to standard JSON syntax.

Compression

Removes line breaks, indentation and whitespace that do not affect data.

Key Sorting

Sorts object keys in alphabetical or Unicode order.

Escaping

Converts quotes, line breaks and other characters to escape sequences.

Common Errors

Single Quotes

✗ Wrong
{'name':'Qudo'}
✓ Correct
{"name":"Qudo"}

Trailing Comma

✗ Wrong
{
  "name": "Qudo",
  "active": true,
}
✓ Correct
{
  "name": "Qudo",
  "active": true
}

Unquoted Keys

✗ Wrong
{name: "Qudo"}
✓ Correct
{"name": "Qudo"}

Unsupported Values

✗ Wrong
undefined, NaN, Infinity
✓ Correct
true, false, null, numbers, strings, objects, arrays

Use Cases

Debug API Responses

Format and inspect API return data for debugging.

Check Request Parameters

Validate API request parameter structures.

Read Compressed JSON

Beautify minified JSON for readability.

Organize Config Files

Format configuration files for better readability.

Inspect Webhook Data

Format webhook payloads for analysis.

Compress JSON

Reduce JSON size for faster data transmission.

Prepare Documentation

Format JSON examples for development documentation.

Validate Data Export

Check browser-exported data for correctness.

Limitations

  • ⚠Standard JSON does not support comments.
  • ⚠JSON keys and strings must use double quotes.
  • ⚠Duplicate keys may be overwritten by the parser.
  • ⚠Very large JSON files may slow down the browser.
  • ⚠Formatting only checks syntax, not business logic correctness.
  • ⚠Large integers in JSON may exceed JavaScript safe integer range.
  • ⚠Do not paste passwords, API keys or access tokens on untrusted websites.

Data & Privacy

JSON data is only parsed and formatted in your browser. It is not uploaded to any server and will not be saved. After refreshing or closing the page, undownloaded data will be cleared. For security, do not paste passwords, API keys or access tokens on any untrusted website.

Frequently Asked Questions

What is the difference between JSON and JavaScript objects?+
JSON is a strict data exchange format. Keys and strings must use double quotes. It does not support functions, comments, or undefined.
Why can't single quotes pass validation?+
Standard JSON requires strings to use double quotes.
Can JSON contain comments?+
Standard JSON does not support comments. Configurations with comments may belong to extended formats like JSONC.
Will formatting change my data?+
Normally it only changes whitespace and indentation. It should not change key values or array order.
Will compressing JSON delete data?+
No. It only removes unnecessary line breaks and whitespace. Spaces inside strings are preserved.
Why does it report a trailing comma error?+
Standard JSON does not allow a comma after the last item in an object or array.
Can it format very large JSON?+
It can handle data of a certain size, but speed depends on file size and device performance.
Will my JSON be uploaded?+
No. All processing is done locally in your browser. Nothing is uploaded or saved.

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Related Articles

  • ▸JSON format and basic syntax guide
  • ▸Common JSON syntax errors and solutions
  • ▸Difference between JSON and JavaScript objects
  • ▸JSON vs JSONC vs JSON5
  • ▸How to handle large integers in JSON
  • ▸How to debug API JSON responses
  • ▸Difference between JSON formatting and compression