365tools

JSON Formatter

Format, minify and validate JSON in your browser. Nothing is sent to any server.

Files processed in your browser — never uploaded
Indent

Input

Output

How JSON Formatter Works

1

Paste your JSON

Paste raw or minified JSON into the input panel on the left. It can be from an API response, a config file, or any JSON source.

2

Format or Minify

Click Format to add indentation and line breaks, or Minify to strip whitespace for the smallest possible output. Validate checks syntax without changing the text.

3

Copy the result

Copy the formatted output to clipboard with one click. The output stays editable so you can adjust it before copying.

Key Features

Format with 2 or 4-space indent

Choose 2-space (JavaScript standard) or 4-space (Python/Java standard) indentation for the formatted output.

Minify JSON

Strip all whitespace to produce the smallest valid JSON string — ideal for reducing API payload sizes before deployment.

Syntax error detection

Invalid JSON triggers an error message showing the exact parser message. Common mistakes like trailing commas and single quotes are caught immediately.

100% browser-based

JSON.parse() and JSON.stringify() run entirely in your browser tab. No data is ever transmitted over the network.

Instant results

There is no server round-trip — formatting and validation happen in microseconds regardless of file size.

Copy to clipboard

One-click copy of the output panel. Works for both formatted and minified output without selecting text manually.

Frequently Asked Questions

Q
What is a JSON formatter?
A
A JSON formatter (also called a JSON beautifier or prettifier) takes compact or unindented JSON and adds proper indentation and line breaks to make it human-readable. It transforms {"name":"John","age":30} into a neatly indented multi-line format that is easier to read and debug.
Q
Is my JSON data sent to a server?
A
No. This tool runs entirely in your browser using JavaScript's built-in JSON.parse() and JSON.stringify() functions. Your data never leaves your device — there are no servers involved.
Q
What's the difference between formatting and minifying JSON?
A
Formatting adds whitespace and indentation to make JSON readable by humans. Minifying removes all unnecessary whitespace to produce the smallest possible JSON string — useful for reducing payload sizes in APIs and web apps.
Q
Why is my JSON invalid?
A
Common JSON errors include: trailing commas (not allowed), single quotes instead of double quotes, unquoted property names, comments (JSON does not support them), and missing commas between elements. The error message shows the exact problem.
Q
Can I format very large JSON files?
A
Yes, up to the limit of your browser's available memory. For very large files (50MB+), processing may take a few seconds. There are no server-side size limits since everything runs locally.

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