JSON Formatter & Validator

Format, indent, and validate JSON entirely in your browser.

Paste JSON on the left to see it formatted on the right. Invalid JSON shows the parser error inline.

Indent:24

Input

Formatted output

{
  "hello": "world",
  "items": [
    1,
    2,
    3
  ]
}

About this tool

Uses the browser's built-in JSON.parse and JSON.stringify. Indent toggle switches between 2-space and 4-space output. No data is sent to a server — your input stays local.

All processing happens entirely in your browser — no input is sent to our servers.