Home/Tools/JSON Formatter

JSON Formatter & Validator

Format, beautify, validate, and minify JSON payloads in real-time. Zero telemetry — runs entirely in your browser.

Input JSON
·
Formatted Output
·
// Formatted JSON will appear here
0 bytes · 0 lines
Advertisement

JSON (JavaScript Object Notation) Standards

JSON is an open standard file format and data interchange format defined in RFC 8259 and ECMA-404. It uses human-readable text to store and transmit data objects consisting of attribute–value pairs and arrays.

Supported JSON Data Types

  • String: Sequence of zero or more Unicode characters wrapped in double quotes (e.g. "hello"). Single quotes are invalid JSON.
  • Number: Signed decimal number (e.g. 42, -3.14, 1.0e10). Hex or octal notation is not supported.
  • Object: Unordered collection of key-value pairs wrapped in curly braces { ... }.
  • Array: Ordered sequence of zero or more values wrapped in square brackets [ ... ].
  • Boolean: Either true or false.
  • Null: The empty value literal null.

Frequently Asked Questions

Why is my JSON invalid even though it looks correct?

Common causes include trailing commas after the last item, using single quotes instead of double quotes for keys/strings, or unescaped special characters inside strings — all of which are valid in JavaScript object literals but not in strict JSON.

What's the difference between formatting and minifying JSON?

Formatting adds indentation and line breaks to make JSON human-readable for debugging. Minifying strips all unnecessary whitespace to produce the smallest possible payload size, which is preferable for production API responses.

Does this tool validate JSON against a schema?

No — it validates that the JSON is syntactically well-formed (parses correctly), not that it matches a specific structure or schema. For schema validation, you'd need a dedicated JSON Schema validator.

Is my JSON data uploaded anywhere when I use this tool?

No, all parsing, formatting, and validation happens locally in your browser using the native JSON.parse/stringify APIs — nothing is sent to a server.

⚡ Related Developer Tools

View All 30+ Tools →
🔐Security

JWT Decoder

Decode JSON Web Tokens securely in your browser with header/payload highlighting and expiration check.

Open Tool →
#️⃣Security

Hash Generator

SHA-256, SHA-512, and SHA-1 cryptographic hashing using browser SubtleCrypto API.

Open Tool →
🔑Security

Password Generator

Cryptographic high-entropy passwords, API tokens, and secure passphrases.

Open Tool →