Quick Answer
A JSON formatter takes a JSON string — often minified into one unreadable line by an API or build tool — and re-renders it with indentation, so objects and arrays become easy to scan. The tool above also validates your input and flags the exact error when something is malformed.
What This Tool Does
You paste JSON into the input box and it comes out the other side formatted and validated. The indentation is adjustable (2 spaces, 4 spaces, or tabs), and because parsing happens locally with the browser’s own JSON engine, a bad input produces a precise, human-readable error rather than garbage output.
Key Features
- Live formatting — results update as you type; no button needed.
- Validation built in — trailing commas, missing brackets and stray quotes are caught and explained.
- Three indent styles — match your project’s style guide in one click.
- Copy or download the result, or keep the original untouched.
How to Use the JSON Formatter
- Paste your JSON into the input box (or click Sample to see it in action).
- Choose your indentation from the dropdown.
- Read the formatted result on the right — if it is invalid, the error appears below the box.
- Click Copy or Download to take the formatted JSON with you.
Examples
{"name":"ToolsHub4u","free":true} becomes:
{
"name": "ToolsHub4u",
"free": true
}Use Cases
- Reading API responses pasted from Postman, curl or browser dev tools.
- Debugging config files (
package.json,.eslintrc,tsconfig.json). - Spotting a misplaced comma before handing JSON to a colleague.
Tips
- Use 2 spaces for JavaScript projects, 4 spaces when JSON is edited by humans in Python or Go ecosystems.
- If the formatter reports an error at a position, count commas first — a missing comma before a key is the most common mistake.
- JSON does not allow comments or trailing commas; strip them before validating.
Privacy
Your JSON never leaves your browser. Parsing and formatting happen locally, so it is safe to paste configs or API payloads that contain secrets.
Conclusion
Formatting JSON should be instant and private. Paste, read, copy — done. Free forever, no account, no uploads.