curlok.com
Free developer tool

JSON Formatter & Beautifier

Paste minified or messy JSON, click Beautify, and copy clean, indented JSON. It also validates as you go and runs 100% in your browser — your data never leaves your machine.

Input JSON
Formatted output

      

What is a JSON formatter?

JSON (JavaScript Object Notation) is the most common format for APIs and config files, but it's often served minified — everything on one line with no spaces — which is impossible to read. A JSON formatter (or "beautifier") re-indents that JSON into a clean, nested, human-readable structure. This tool also validates your JSON and points out exactly where a syntax error is.

How to use it

  1. Paste your JSON into the Input box on the left.
  2. Click Beautify (or press Ctrl/ + Enter). Choose 2 spaces, 4 spaces, or tabs.
  3. Copy the clean result from the Output box with the Copy button.

Need the opposite? Minify collapses your JSON back to a single compact line.

Is my data safe?

Yes. All formatting happens locally in your browser using JavaScript — your JSON is never uploaded to any server. You can even use it offline once the page has loaded.

Related tools

Working with XML instead? Try the XML Formatter. Debugging an API or webhook? Create a free endpoint to inspect exactly what it sends.