JSON Formatter & Validator — Pretty Print or Minify

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Paste messy JSON — get it pretty-printed, validated, or minified. Errors point to where the string broke.

Your JSON

How to use this tool

1. Paste your JSON into the box.
2. Press Format (pretty) for readable indented JSON, or Minify for the smallest production string.
3. Invalid JSON shows the error and its position; valid JSON shows size stats and a preview.
4. Copy result puts the output on your clipboard.

Example

Input: {"b":2,"a":[1,2,3]} → formatted:

{"b": 2,
 "a": [
  1,
  2,
  3
 ]
}

Minified: {"b":2,"a":[1,2,3]}

The formula

validation = JSON.parse(); pretty = JSON.stringify(obj, null, 2); minify = JSON.stringify(obj)

What the result means

A valid badge means the parser could build a complete object from your text — the same engine every browser uses. The char-saved figure tells you how much the minified version will shrink your payload. Errors include the position, so a missing comma is a 10-second fix instead of a 10-minute hunt.

Frequently asked questions

Is my JSON sent anywhere?

No. Parsing, formatting and minifying all happen in your browser — API responses and config files never leave your device. Never paste credentials into any online tool anyway, even this one.

Why does my JSON fail with 'Unexpected token'?

The three classics: trailing commas, single quotes instead of double quotes, and comments — JSON allows none of them. The error position points to the first offender.

Does it preserve key order?

Yes — modern JavaScript objects preserve insertion order for string keys, so your keys stay in the order they appear.

Can it handle big files?

Comfortably into the hundreds of KB. Multi-megabyte JSON may slow the page — the browser's parser is the limit, not this tool.

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Explore the island world

• Circuit Cove — the island where this tool lives.
• The Main Island — drive the boat, explore the whole world.
• The 90s Kids Island — where most of us started.

Privacy & data: this tool runs entirely in your browser — nothing you type is uploaded, saved or sent anywhere. · Disclaimer: all processing happens locally in your browser — never paste production secrets or private data into any online tool, including this one. · Privacy Policy · Disclaimer