JSON Formatter
Pretty-print, minify and inspect JSON instantly.
What does this tool do?
This formatter parses your JSON and reprints it with consistent indentation, so deeply nested API responses, config files and log payloads become readable at a glance. It can also do the opposite — strip every unnecessary space and newline to minify JSON for production payloads. Formatting and minifying both run through a real JSON.parse, so anything that comes out the other side is guaranteed valid.
How to format JSON
- 1Paste or type your JSON into the input panel on the left.
- 2Choose an indent style — 2 spaces, 4 spaces or a tab.
- 3Click Format to pretty-print, or Minify to collapse it to one line.
- 4Copy the result or download it as a .json file.
Handling large files
Formatting only runs when you click a button, not on every keystroke, so pasting a multi-megabyte JSON file won't freeze the page while you're typing. If your JSON has a syntax error, the tool points at the exact line and column so you don't have to scan the whole file by eye.
Frequently asked questions
›Is my JSON uploaded anywhere?
No. Parsing, formatting and minifying all happen in your browser using the built-in JSON.parse and JSON.stringify — nothing is sent to a server, even for very large files.
›Why does it say my JSON is invalid?
The error message includes the line and column where parsing failed. Common causes are trailing commas, single quotes instead of double quotes, and missing quotes around object keys — JSON is stricter than JavaScript object literals.
›What's the difference between Format and Minify?
Format adds indentation and line breaks to make JSON easy to read. Minify removes all whitespace to produce the smallest possible payload — useful when you're about to send the JSON over a network.
›Can it handle very large JSON files?
Yes, within reason. The tool relies on the browser's native JSON parser, which is fast, and only runs on button clicks rather than every keystroke. Extremely large files (well beyond typical API responses) may still take a moment.
›Does it support JSON5 or JSONC (comments, trailing commas)?
No — this tool enforces strict JSON per the spec, the same rules your programming language's JSON parser uses. If you need to preserve comments, JSON isn't the right format.