Developer

JSON Formatter & Validator

Validate and pretty-print JSON safely offline. Processing stays on your device.

How to Use

  1. Paste JSON or upload a .json file.
  2. Format to pretty-print or Minify to compress.
  3. Copy or download the result; fix errors shown inline.

Key Features & Privacy Advantage

  • All processing happens locally in your browser. Your files are never uploaded to a server.
  • JSON.parse validation with readable errors.
  • Pretty and minify modes.
  • Copy and download.

Technical Breakdown

JSON.parse provides structural validation. Pretty mode uses JSON.stringify with indentation; minify uses compact stringify. Trailing commas and comments are rejected — they are not valid JSON.

Ideal for debugging API payloads without pasting secrets into online formatters.

Frequently Asked Questions

Do you store my JSON?

No. All processing happens locally in your browser. Your files are never uploaded to a server.

Why is my JSON invalid?

Common causes: trailing commas, single quotes, or unquoted keys.

Can I minify?

Yes — use the Minify action.

Large files?

Very large documents may slow the tab; try splitting payloads.