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Free Tool

JSON Formatter & Validator

Paste JSON to instantly format, validate, and minify. Errors reported with line numbers. No data leaves your browser.

How to use the JSON Formatter

  1. Paste your JSON into the input box on the left.
  2. Click Format to prettify with 2-space indentation, or Minify to compress it into a single line.
  3. If your JSON is invalid, the tool shows the exact error with line and column numbers.
  4. Click Copy or Download .json to save the result.

What is JSON?

JSON (JavaScript Object Notation) is the most widely-used data interchange format on the web. APIs, configuration files, databases, and logging systems all use JSON because it is lightweight, human-readable, and language-independent.

Common JSON errors include trailing commas, single quotes (instead of double), unquoted keys, and incorrect nesting. This validator catches all of them instantly.

Features

  • ⚡Instant validation — no server round-trip
  • 🔍Error line & column highlighting
  • 🗜️One-click minify (remove whitespace)
  • ✨Prettify with customizable indent
  • 📋Copy to clipboard
  • 💾Download as .json file
  • 🔒Runs 100% in your browser
  • 🆓Free — no account, no ads

Related: JSON Minifier · JSON Validator

Frequently Asked Questions

Is this JSON formatter free?

Yes. It is completely free, with no signup, no ads and no limits on how much JSON you can format.

Is my JSON data sent to a server?

No. All formatting and validation happens entirely in your browser using JavaScript — your data never leaves your device.

What is the difference between format and minify?

Format (beautify) adds indentation and line breaks so JSON is easy to read. Minify removes all whitespace to produce the smallest possible single-line output.

How does it report JSON errors?

Invalid JSON is reported with the exact error message plus the line and column where parsing failed, so you can fix it quickly.

What are common JSON errors it catches?

Trailing commas, single quotes instead of double quotes, unquoted keys, missing brackets and incorrect nesting are all detected instantly.

Can I download the formatted JSON?

Yes. You can copy the result to your clipboard or download it as a .json file with one click.