Amumu Webtools

Free Online JSON Formatter & Validator

Format, minify, and validate JSON instantly. All processing runs in your browser.

Format and validate JSON, with pretty-print, minify and copy.

Editor

What is JSON Formatter & Validator?

A JSON Formatter & Validator lets you paste raw JSON and get a readable, indented version. It also checks for syntax errors and can minify JSON to a single line. This tool runs entirely in your browser—no server upload.

How to Use This Tool?

Paste your JSON in the editor. Click Format to pretty-print, Minify to compress, or Clear to start over. Invalid JSON will show an error message with details.

  1. Paste or type your input in the tool area above.
  2. Adjust any options (format, encoding, etc.) if needed.
  3. Use the action buttons to format, convert, or process.
  4. Copy or download the result as needed.

100% Secure & Client-Side

All processing runs 100% in your browser. We do not upload, store, or transmit your data to any server. Your privacy and data security are guaranteed.

Frequently Asked Questions

JSON (JavaScript Object Notation) is a lightweight data format used for APIs and config files. This tool formats and validates it.