JSON Formatter

What is a JSON Formatter?

A JSON formatter (also called a JSON beautifier or pretty-printer) takes raw, unformatted JSON text and adds consistent indentation, line breaks, and spacing so it is easy for humans to read. Whether you are debugging an API response, editing a config file, or exploring a database export, formatted JSON is drastically easier to navigate than a single-line blob of text.

This formatter also lets you minify JSON (strip all whitespace for compact storage or transmission) and sort keysalphabetically — handy for diffing two JSON objects where key order might differ.

How to use this JSON Formatter

1. Paste your JSON into the input pane on the left, or drag and drop a .json file directly onto the dropzone. Files up to 200 MB are supported.
2. Choose your indent style — 2 spaces, 4 spaces, or tabs. The output updates instantly as you type.
3. Toggle "Sort keys" if you want object keys arranged alphabetically. This makes structural diffs much cleaner.
4. Copy or download the formatted output using the buttons below. Download saves a .json file with a clean filename.
5. Share your JSON with the Share button — it compresses your input into the URL hash using LZ-string so the link restores the exact state. The URL never changes the canonical path (no SEO pollution).

Why privacy matters for JSON data

JSON is the lingua franca of APIs, databases, and configuration. That means the JSON you need to format is often sensitive: API keys embedded in config responses, personally identifiable information from user endpoints, internal service payloads, database exports containing healthcare or financial records.

Most online JSON formatters send your data to their servers for processing — either intentionally to log it, or as a side effect of a server-rendered architecture. This formatter is different:all processing happens in your browser tab using JavaScript. The formatted JSON is computed by your CPU, stored in your browser's memory, and displayed on your screen. Nothing is sent over the network. You can verify this yourself by opening DevTools → Network and watching for outbound requests while you format.

For large files (multi-MB JSON), processing runs in aWeb Worker — a background thread — so the browser UI stays perfectly responsive while your data is being parsed and formatted.

What does "Fix JSON" do?

The Fix JSON button uses the open-source jsonrepair library to automatically correct the most common JSON mistakes:

• Trailing commas after the last item in objects or arrays
• Single-quoted strings instead of double-quoted
• Unquoted property names (JavaScript object literal syntax)
• Missing or extra brackets and braces
• Comments (// … or /* … */) that are valid in JSONC but not standard JSON
• Concatenated JSON objects or truncated responses

Fix JSON is intentionally shown as a secondary action — it is a useful escape hatch but the repaired output should always be verified before being used in production.