JSON Formatter
Free online tool · runs in your browser
Beautify JSON with instant validation.
Quick tutorial
- 1Paste JSON into the input panel.
- 2Click Format to beautify with 2-space indentation.
- 3Use Copy or Download to export the result.
Free online json formatter
Use this free online JSON formatter to format JSON, beautify, and pretty-print instantly. Paste messy or minified JSON, click Format, and get readable 2-space indented output with syntax validation. Everything runs locally in your browser, so API payloads, config files, and secrets never leave your device. It is a fast JSON beautifier and pretty printer for developers who need clean JSON without installing an editor plugin. For a longer walkthrough of safe workflows, read our guide on formatting JSON in the browser.
Documentation last reviewed .
When to use this JSON formatter
Use this page when you need readable indentation for an API response, a config blob from chat, or a minified payload from a log. Paste the text, click Format, and copy the result. The formatter validates while it pretty-prints, so broken JSON fails with a clear error instead of silently producing nonsense.
Prefer this over pasting production data into unknown third-party sites. Formatting runs with your browser’s JSON.parse / JSON.stringify path — ShadowReference does not receive the contents of the input panel.
Formatting tips for everyday debugging
If Format fails, check for trailing commas, comments, or single quotes. Those are valid in some JavaScript contexts but not in JSON. After you have a clean document, use Expand/Collapse in the result tree to navigate large objects without losing your place.
Need the reverse? Send the same document through the JSON Minifier. Need only a pass/fail check? Use the JSON Validator. Guides on this site explain safe workflows for sensitive payloads.
How to use JSON Formatter
- Paste JSON into the input panel.
- Click Format to beautify with 2-space indentation.
- Use Copy or Download to export the result.
Limitations
- Very large JSON files may slow down the browser.
- Comments and trailing commas are not valid JSON.
Example
Input
{"a":1,"b":[2,3]}Output
{
"a": 1,
"b": [2, 3]
}FAQ
Frequently Asked Questions
What is a JSON formatter?
A JSON formatter (also called a JSON beautifier or pretty printer) takes compact or messy JSON and rewrites it with consistent indentation and line breaks so you can read and debug it.
Is this JSON formatter free?
Yes. This online JSON formatter is free, with no signup, no watermarks, and no file-size account limits beyond what your browser can handle.
Does the JSON beautifier upload my data?
No. Formatting and validation run entirely in your browser. Your JSON is never sent to a ShadowReference server.
Can I pretty-print minified JSON?
Yes. Paste minified JSON and format it to restore readable indentation. Use the JSON Minifier if you need the reverse.
Why did formatting fail?
Strict JSON rejects trailing commas, comments, single-quoted strings, and unquoted keys. Fix the first reported syntax error and try again.
Should I use this instead of Prettier?
Use Prettier or jq in your project for team standards. This tool is for private, in-browser formatting of snippets you already have on screen.
Does this send my JSON to a server?
No. All formatting happens locally in your browser.
Can I minify JSON here?
Use the JSON Minifier tool for compact output.
Is JSON Formatter free to use?
Yes. JSON Formatter on ShadowReference is free, with no account, no watermarks, and no server-side processing.
Does this tool send my data to a server?
No. All processing happens locally in your browser. Your input never leaves your device.
Related guides
Deeper reading on private, browser-based workflows for json formatter and related tools.
- How to Format JSON Safely in Your Browser — Learn how to pretty-print and validate JSON locally without uploading API payloads or secrets to a third-party server.
- Why Private Browser Developer Tools Matter — Why ShadowReference runs every tool in your browser, what “no upload” really means, and how that helps day-to-day engineering work.