JSON Formatter

Paste messy or minified JSON and get it back clean, indented, and validated in one click. This JSON Formatter pretty-prints valid JSON, flags the exact syntax error when it is invalid, and can also minify JSON down to a single line. Everything runs in your browser, so the data you paste never leaves your device.

Raw JSON

Formatted Output

Indent:

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Why use JSON Formatter?

JSON (JavaScript Object Notation) is strict in ways that trip people up: keys and strings must use double quotes, there are no trailing commas, no comments, and no single quotes. A single stray comma is enough to make an entire payload fail to parse. This formatter uses the same JSON.parse engine your application uses, so if it validates here, it will validate in your code. Beautifying adds indentation and line breaks so you can actually read a nested structure, which is invaluable when you are staring at a 4,000-character API response that arrived as one line. Minifying does the reverse, removing every optional space and newline to shrink the payload for transport or storage. Because the entire process is client-side, you can safely paste tokens, internal API responses, or configuration without it ever touching a network. Close the tab and the data is gone.

Key benefits

Spot the exact line and reason a JSON payload fails to parse
Switch between human-readable (beautified) and compact (minified) in one click
Runs fully client-side, nothing you paste is uploaded to a server
Choose 2, 4, or 8-space indentation to match your project style
No length limit beyond your browser memory, paste whole API responses

Features

Uses the native JSON.parse engine, so validation matches what your code sees
Inline error messages for trailing commas, single quotes, and unquoted keys
Beautify and minify from the same input
Monospaced, scrollable output panel for large objects
One-click clipboard copy

Popular use cases

Debugging an API response that arrived as one unreadable line
Cleaning up a config file (package.json, tsconfig, app settings) before committing
Validating a webhook payload before wiring it into your handler
Minifying JSON to embed in a query string or environment variable

How to use JSON Formatter

1
Paste your JSON
Type or paste raw JSON into the "Raw JSON" box on the left.
2
Choose an indent
Pick 2, 4, or 8 spaces of indentation from the Indent dropdown.
3
Format or minify
Click "Format / Beautify" to pretty-print, or "Minify" to collapse it to one line. Invalid JSON shows the exact parser error.
4
Copy the result
Use the Copy button to grab the formatted output for your editor, API client, or config file.

Frequently asked questions

Why is my JSON invalid?

The most common causes are trailing commas after the last item, single quotes instead of double quotes, unquoted object keys, comments (JSON does not allow them), or a missing closing bracket. The formatter shows the parser error message so you can jump straight to the problem.

Does this beautify or minify?

Both. "Format / Beautify" expands JSON with your chosen indentation for readability; "Minify" strips all whitespace to produce the smallest valid one-line version.

Is my data uploaded anywhere?

No. Formatting and validation happen entirely in your browser using the built-in JSON parser. Nothing you paste is sent to or stored on our servers.

What indentation can I use?

You can choose 2, 4, or 8 spaces. Two spaces is the common default for JavaScript and web projects; pick whatever matches your codebase.

Will it fix my JSON automatically?

No tool can safely guess your intent, so it validates rather than auto-repairs. It pinpoints the error (for example a trailing comma) and you make the one-character fix.

Related guides

Fix Invalid JSON: The 5 Errors That Break Every Payload

Last reviewed: July 2026

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