Online JSON Formatter

A JSON formatter takes raw or minified JSON and rewrites it with consistent indentation and line breaks, making it readable at a glance. The data itself doesn't change — only the whitespace does. JSON Pretty also lints the input as it formats, so syntax errors get flagged before they reach your code.

Paste your JSON into the box above and click Format. JSON Pretty validates the structure, applies clean indentation, and loads the result into the full editor for further inspection — all without leaving your browser.

Yes. The parser runs off the main thread, so multi-megabyte JSON files format without freezing the page. You can also upload a .json file from disk directly into the formatter.

Yes. When you click Format, JSON Pretty parses the input first; if anything is wrong, the exact line and a snippet of the broken fragment are surfaced so you can fix it without scanning the whole document.

All formatting and validation happen locally in your browser. JSON Pretty doesn't send your data to a server, doesn't log it, and doesn't store it anywhere outside your machine.

A typical online JSON formatter is a single paste-box on a webpage. JSON Pretty adds a Chrome extension that auto-formats every JSON response in your browser tab, plus a full editor with syntax highlighting, search, and copy-by-path — all running locally.