Free JSON Formatter & Validator

Format, validate and minify JSON online for free, right in your browser. Beautify messy JSON, catch syntax errors with the exact line and column, and copy the result in one click.

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About This Online JSON Formatter & Validator

This free JSON formatter helps you beautify, validate and minify JSON directly in your browser — no upload to a server required. Paste raw or minified JSON, fix syntax errors using the exact error location, and get clean, readable JSON in seconds.

It's built for developers who need a fast way to sanity-check an API response, a config file, or JSON copied from logs, without pasting sensitive data into a third-party server.

How to Format or Validate JSON Online

1. Paste your JSON

Paste or type your JSON into the input box above, whether it's a single object, an array, or a large nested structure.

2. Format, validate or minify

Click "Format / Beautify" to pretty-print your JSON with proper indentation, "Validate" to check it without changing it, or "Minify" to compress it to a single line.

3. Fix errors quickly

If your JSON is invalid, the tool shows a clear error message along with the line, column and a short preview of the surrounding text, so you can find the problem right away.

4. Copy the result

Once your JSON is formatted or minified the way you want, click "Copy" to copy it straight to your clipboard.

Why Use a JSON Formatter & Validator?

  • Turn minified or messy JSON into readable, indented JSON.
  • Catch syntax errors — missing commas, unquoted keys, trailing commas — before they break your code.
  • Minify JSON for production use or smaller payloads.
  • Quickly inspect API responses or config files.
  • Everything runs locally, so sensitive JSON never leaves your browser.

Frequently Asked Questions

Is this JSON formatter free?

Yes. This online JSON formatter and validator is completely free to use, with no sign-up and no limit on how many times you can use it.

Is my JSON sent to a server?

No. All formatting, validation and minifying happens locally in your browser using JavaScript. Your JSON is never uploaded or sent to a server.

Can this tool show me where the error is in my JSON?

Yes. When your JSON is invalid, the tool reports the line and column of the problem along with a short preview of the surrounding text so you can find and fix it quickly.

What is the difference between formatting and minifying?

Formatting (beautifying) adds indentation and line breaks to make JSON easy to read. Minifying removes all unnecessary whitespace to make the JSON as small as possible, which is useful for production or transmission.

Does formatting change the data in my JSON?

No. Formatting and minifying only change whitespace and indentation. The keys, values and structure of your JSON stay exactly the same.

Is there a size limit for the JSON I can format?

There's no hard limit enforced by the tool, but since everything runs in your browser, extremely large JSON files (many megabytes) may be slower depending on your device.