About this json formatter

This formatter parses the input as JSON and writes the same parsed value with predictable whitespace. Formatting changes presentation, not the object or array structure; minifying removes insignificant whitespace.

RFC 8259 permits an object, array, string, number, boolean or null at the document root. This tool accepts each of those values instead of requiring every document to begin with an object.

JSON formatting is essential when working with APIs, configuration files, or data interchange. Whether you're a developer debugging API responses, a DevOps engineer managing configuration, or a data analyst reviewing datasets, a reliable JSON formatter saves time and prevents errors. This free online tool gives you instant access to professional-grade JSON formatting without installing software or creating an account.

Beyond basic formatting, this tool provides three critical operations: format for readability (perfect for reviewing API responses or large config files), validate to catch JSON syntax errors before they cause problems in production, and minify to reduce file size for storage or transmission. Each operation preserves data integrity while meeting different use-case requirements.

The tool handles edge cases that catch many developers off guard: RFC 8259 compliance, duplicate key detection, high-precision number handling, and support for root-level primitives. Get immediate feedback on why your JSON is invalid and fix issues in seconds—no more cryptic parsing errors or silent data loss.

How to use this tool

01
Paste the JSON document
Input is read only by JavaScript in the current tab. Comments and trailing commas are rejected because they are not JSON.
02
Choose the operation
Format with 2 or 4 spaces, validate without changing the value, or minify to one compact line.
03
Check and export
Read the validation message, then copy the result or download it as a JSON file.

Worked examples

Pretty-print a compact object

Input

{"name":"Ada","skills":["math","code"]}

Result

{
  "name": "Ada",
  "skills": [
    "math",
    "code"
  ]
}

Why a trailing comma fails

Input

{"ready":true,}

Result

Invalid JSON: a comma cannot appear before the closing brace.

Limits and edge cases

Duplicate object names cannot be preserved by the browser JSON parser. The tool detects them and refuses to format or minify rather than silently retain only the last value.
JavaScript numbers have finite range and precision. The tool refuses unsafe integers plus decimal or exponent values that native parsing would round, overflow or underflow; quote exact identifiers and high-precision values.
JSON does not include comments, NaN, Infinity, hexadecimal numbers, single-quoted strings or trailing commas.
Formatting normalizes whitespace and cannot preserve the original spelling of equivalent numbers or escape sequences.

Standards and references

Common questions

Is JSON formatting the same as validating?

Formatting must parse the document first, so a successful format also confirms valid JSON syntax. Validate is useful when you only need a clear pass or error message.

Does this JSON formatter upload my data?

No. Parsing, formatting, copying and file creation happen in the current browser tab. The page does not send the JSON to this site.

JSON Formatter workspace