JSON Formatter & Validator — The Complete Guide

JSON (JavaScript Object Notation) is the most common data format on the web. Whether you're debugging an API response, configuring a tool, or working with data — being able to format, validate, and read JSON is essential.

JSON is a lightweight data format that's easy for humans to read and machines to parse. It uses key-value pairs and supports strings, numbers, booleans, arrays, objects, and null.

Here's what messy JSON looks like vs. formatted:

{"name":"John","age":30,"skills":["JavaScript","Python","SQL"],"address":{"city":"Vancouver","country":"Canada"}}

{
  "name": "John",
  "age": 30,
  "skills": [
    "JavaScript",
    "Python",
    "SQL"
  ],
  "address": {
    "city": "Vancouver",
    "country": "Canada"
  }
}

1. Open the JSON Formatter — go to FileNaut's JSON Formatter.
2. Paste your JSON — paste raw JSON into the input area.
3. Instantly formatted — the tool automatically formats, syntax-highlights, and validates your JSON.
4. Copy the result — click Copy to grab the formatted output.

No signup, no server upload — your data stays in your browser.

• Missing quotes around keys — JSON requires double quotes: "name" not name or 'name'.
• Trailing comma — the last item in an array or object must NOT have a comma after it.
• Single quotes — JSON only supports double quotes ("), not single quotes (').
• Missing brackets — every { needs a }, every [ needs a ].
• Unescaped special characters — backslashes, quotes, and newlines inside strings must be escaped.