JSON Formatter
Format, validate, and minify JSON — instantly, in your browser.
Paste messy or minified JSON and instantly get it beautifully formatted and validated — or minify it to shrink the payload. Everything runs locally in your browser, so your data never leaves your device.
Runs entirely in your browser — nothing is uploaded.
How to use the json formatter
- 1Paste your JSON into the input box.
- 2Click Format to pretty-print it, or Minify to compact it.
- 3Copy the result — invalid JSON is flagged with the exact error.
Frequently asked questions
Is my JSON uploaded anywhere?
No. Formatting and validation happen entirely in your browser — nothing is sent to a server.
What does minify do?
Minifying removes all whitespace and line breaks to produce the smallest valid JSON, useful for reducing payload size.
Why is my JSON invalid?
The tool shows the parser's exact error, commonly caused by trailing commas, single quotes, or unquoted keys.