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JSON Formatter

Beautify, minify and validate JSON in one click, with automatic error detection.

What is a JSON formatter?

JSON is the most common format for exchanging data between front and back end, but machine-generated JSON is often crammed into one unreadable line. This online JSON formatter instantly beautifies messy JSON into a clear indented structure — or minifies it to the smallest size — while validating the syntax and pinpointing errors.

How to use

  1. Paste your JSON into the input box on the left.
  2. Choose the indentation (2 spaces, 4 spaces or Tab).
  3. Click Beautify to make it readable, or Minify to collapse it to one line.
  4. The result appears on the right and can be copied in one click. If the JSON is invalid, the status bar explains why.

Common use cases

  • Inspect the structure of an API response.
  • Normalize config files to a consistent indentation style.
  • Minify JSON before shipping to reduce payload size.
  • Validate hand-written JSON before your code parses it.

Frequently Asked Questions

Does this tool upload my data?

No. All formatting, minifying and validation run locally in your browser with JavaScript. The JSON you paste is never sent to a server or stored.

Can it handle large JSON files?

Yes, as long as it fits in your browser memory. Files of a few MB are processed instantly; for very large files, use a desktop browser.

Why do I get a "syntax error"?

Common causes are trailing commas, unquoted keys, single quotes instead of double quotes, or comments. The error message points to the approximate location so you can fix it.

What is the difference between beautify and minify?

Beautify adds indentation and line breaks for readability and debugging; minify strips all whitespace into one line for the smallest size, ideal for transport or embedding.