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JSON Formatter and Validator

Format, beautify, minify, and validate JSON data instantly in your browser. Fast, private, and free JSON tool.

What Is a JSON Formatter?

JSON (JavaScript Object Notation) is the common format for sending data between apps and APIs. When it arrives on your screen it is often one long, unreadable line. A JSON formatter indents every object and array, so you can see the structure at a glance and spot misplaced commas or missing braces.

Why Validate JSON?

A single extra comma makes an entire JSON document invalid, and the error message is usually hard to read. Our validator checks the whole document and reports the exact problem, saving you the slow process of guessing where the structure broke.

When to Use Minify

APIs and configuration files can ignore whitespace, so removing it shrinks file size and transfers faster. Minify is perfect right before you paste JSON into a payload or a cloud config.

Frequently Asked Questions

Is my JSON sent to a server?
No. Formatting and validation run entirely in your browser, so your data never leaves your device.
What causes invalid JSON?
Trailing commas, missing closing braces, unquoted keys, and single quotes instead of double quotes are the most common causes.
Does the formatter support nested objects?
Why does my JSON show an error?
The validator checks for missing commas, unclosed braces, and misplaced quotes. Fix the highlighted line for valid JSON.
Can I minify JSON after formatting?
Yes — switch to the Minify option to compress formatted JSON into a single line, perfect for APIs and storage.
Yes. Any depth of objects and arrays is indented and color-coded by structure in the output.
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