JSON Formatter & Validator
Paste JSON below to pretty-print, validate, or minify it. Parsing happens locally in your browser — nothing is sent to a server, so it's safe for API keys, tokens, and production payloads.
How it works
This tool uses the browser's native JSON.parse — the same strict parser Node.js
and every major API framework uses — so if your JSON validates here, it will
parse anywhere. Formatting is JSON.stringify with your chosen indent.
Invalid input produces the parser's real error plus the line and column where it occurred, which makes hunting a missing comma in a large payload much faster than eyeballing it.
FAQ
Is it safe to paste sensitive JSON here?
Yes. The formatter runs entirely in your browser with JavaScript's built-in JSON parser. Nothing you paste is uploaded, logged, or stored.
Why did my JSON fail to validate?
Common causes: trailing commas, single quotes instead of double quotes, unquoted keys, or comments — none of which strict JSON allows. The error message shows the line where parsing stopped.
What's the difference between Format and Minify?
Format pretty-prints with indentation for reading; Minify strips all whitespace into a single line for smaller payloads.