JSON Formatter & Pretty Printer
Prettify, minify, and validate JSON online in one click. Paste compact JSON and this free tool reformats it with clean indentation instantly — or switch to JSON Minify to compress it back. Every operation runs locally in your browser.
Why format JSON?
JSON is the most common data format for APIs, configuration files, and storage. When it arrives minified on a single line, it is hard to read: nested objects blur together and syntax mistakes are easy to miss. A JSON formatter reformats the data so every key, array, and value sits on its own readable line.
This page is the documentation for the free JSON formatting, validation, and minification tool built into DataFormatter — paste JSON into the editor and everything is detected and formatted automatically.
How to format JSON online
- Open the free JSON formatter tool from DataFormatter.
- Paste your compact JSON, or type it directly into the editor.
- The JSON is detected automatically and pretty-printed with 2-space indentation.
- Optionally switch to JSON Minify to compact it, or validate that your JSON is well-formed.
Features
- Automatic JSON detection — no setup required
- Pretty-print with standard 2-space indentation
- JSON minifier to compress output back to a single line
- Same-page validation with clear error messages
- Line numbers, bracket matching, and folding in the editor
- 100% client-side: your data never leaves the browser
Frequently asked questions
What is a JSON formatter?
A JSON formatter takes compact or minified JSON and re-writes it with readable indentation and line breaks, making nested objects and arrays easy to scan.
Is this JSON formatter free and safe to use?
Yes. The tool is free, requires no account, and runs entirely in your browser. Your JSON is never sent to a server.
Can it also minify JSON or validate it?
Yes. Use the tools in the app for JSON Minify and JSON validation. Invalid JSON is reported with a clear message instead of failing silently.