What is JSON?
JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write and easy for machines to parse and generate. It is based on a subset of the JavaScript Programming Language Standard.
Why Use a Formatter?
Raw JSON is often minified to save space, making it nearly impossible to read. Our formatter adds indentation and line breaks, transforming dense blobs of text into a structured, readable hierarchy.
Key Features
Pro Tip
You can use the "Download" button to save your formatted JSON directly as a file. This is useful for large configurations or data exports.
A Quick Walkthrough
Imagine you've copied an API response from your browser's network tab and it arrives as a single 4 KB line: {"users":[{"id":1,"name":"Ada","roles":["admin","editor"]}, ...]}. Pasting that into the input pane and clicking Beautify with 2-space indentation turns it into a 60-line tree where you can immediately see that users[3].roles is an empty array — the bug you were chasing. Once you've spotted the issue, click Minify to put it back on one line for pasting into a curl command, or Download to keep a fixture file for your test suite.
Common JSON Errors and What They Mean
JSON is strict, and most errors fall into a small handful of categories. Trailing commas after the last element of an array or object are the most frequent — JavaScript allows them, JSON does not. Single quotes around keys or strings will fail; JSON requires double quotes everywhere. Unescaped backslashes in Windows file paths trip people up: write "C:\\\\Users\\\\Ada", not "C:\Users\Ada". And comments (// or /* */) are not valid JSON — if you need annotations, use a sibling key like "_comment" instead. The validator will point at the exact line and column where parsing failed so you can fix the offending character without scanning the whole file.
Frequently Asked Questions
Does this work offline?
Yes. Once the page loads, formatting and validation run entirely in your browser using the native JSON.parse and JSON.stringify functions — no network calls.
Is there a size limit?
There's no hard cap, but very large inputs (over ~10 MB) may briefly freeze the tab while the browser parses them. For huge files, prefer command-line tools like jq.
Will minification change my data?
No. Minification only removes insignificant whitespace; key order, values, and types stay identical. The minified and beautified outputs parse to the same object.
Can I sort keys alphabetically?
Not currently in this tool — JSON technically treats object keys as unordered, but sorted keys help when diffing config files. Use a follow-up step in your editor or a script if you need that.