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JSON Formatter & Beautifier - Format JSON Online

Indent:
Input JSON
Formatted Output

About the JSON Formatter

JSON (JavaScript Object Notation) is the most widely used data interchange format on the web. APIs return it, configuration files rely on it, and databases store it. But raw JSON from a minified API response or a compact log line is notoriously hard to read. Our JSON Formatter takes that compressed blob and transforms it into a neatly indented, syntax-highlighted document you can scan in seconds.

Unlike server-based formatters, this tool processes everything inside your browser. That means your data stays private, results appear instantly, and there is no file-size upload limit imposed by a backend.

How to Use the JSON Formatter

Using the formatter is straightforward. Paste your raw or minified JSON into the input editor on the left. The formatted output appears automatically in the right-hand pane. You can choose your preferred indentation level (two spaces, four spaces, or tabs) using the controls above the editor. When you are happy with the result, click the copy button to place the formatted JSON on your clipboard, ready to paste into your code editor or documentation.

Features

  • Customisable indentation. Pick 2-space, 4-space, or tab indentation to match your project conventions.
  • Syntax highlighting. Keys, strings, numbers, booleans, and null values are colour-coded for quick visual parsing.
  • Instant error detection. Invalid JSON triggers a clear, line-specific error so you can fix issues on the spot.
  • One-click copy. Copy the entire formatted output to your clipboard with a single button press.
  • Privacy-first. No server calls, no analytics on your input data. Everything stays in the browser.

Common Use Cases

Developers frequently reach for a JSON formatter when debugging REST API responses that arrive as a single long line. It is also useful when reviewing configuration files stored in version control, preparing sample payloads for documentation, or simply making sense of deeply nested data structures. In team settings, consistent formatting also reduces diff noise in pull requests.

Frequently Asked Questions

What does a JSON formatter do?
A JSON formatter takes compact or poorly indented JSON and restructures it with consistent indentation and line breaks so that nested objects and arrays are easy to read. It does not change the data itself, only the whitespace and formatting.
Is my data safe when I paste it here?
Yes. This tool runs entirely in your browser using JavaScript. Your JSON is never sent to a server, so sensitive data such as API keys or personal information stays on your machine.
Can I choose the indentation level?
Absolutely. You can select 2 spaces, 4 spaces, or tab indentation depending on your project's style guide or personal preference.
What happens if my JSON is invalid?
The formatter will display a clear error message indicating where the syntax problem is. You can fix the issue and try again, or switch to the JSON Validator tool for more detailed diagnostics.
Can I format large JSON files?
Yes. Because the tool runs client-side, performance depends on your browser and device. Most modern browsers handle JSON files up to several megabytes without issues.