JSON Formatter & Prettifier

Paste JSON to format, minify, or validate it instantly — free, no signup, runs in your browser.

✓ Free ✓ No Signup ✓ Runs in Browser ✓ Nothing Uploaded
Input
Output
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How to use the JSON Formatter

1

Paste your JSON

Paste raw, minified, or messy JSON into the input box on the left.

2

Click Prettify or Minify

Prettify adds clean indentation for readability. Minify removes all whitespace for compact storage.

3

Copy the output

Click "Copy Output" to copy the formatted JSON to your clipboard in one click.

Frequently Asked Questions

Does this tool send my JSON to a server?

No. The JSON formatter runs entirely in your browser using JavaScript. Your data never leaves your device — nothing is uploaded or stored anywhere.

What is the difference between Prettify and Minify?

Prettify adds line breaks and indentation to make JSON human-readable. Minify removes all whitespace to produce the smallest possible JSON string — useful for APIs, config files, and localStorage.

Why is my JSON showing a validation error?

Common issues: trailing commas (not valid in JSON), single quotes instead of double quotes, unquoted keys, or comments. JSON is a strict format — use the error message in the status bar to locate the problem.

Can I format large JSON files?

Yes. Since processing runs in your browser, large files depend on your device's RAM. Files up to ~10 MB format instantly on modern computers. Very large files (100 MB+) may slow down your browser tab.