Paste JSON, beautify or minify it instantly, and get precise error locations if it's invalid. Free, no signup, nothing uploaded.
JSON (JavaScript Object Notation) is the standard format for exchanging data between APIs, config files, and applications — but it's often delivered minified (all on one line) or with inconsistent formatting, which makes it hard to read and debug. This tool re-indents it for readability, or strips whitespace entirely when you need the smallest possible payload.
Everything runs locally using your browser's built-in JSON parser — nothing is ever sent anywhere.
Yes — since everything runs in your browser using the native JSON parser, there's no server upload size limit; very large files are only limited by your device's memory.
Format (beautify) adds indentation and line breaks for readability; minify strips all unnecessary whitespace to produce the smallest possible file size — both keep the underlying data identical.
These are your browser's native JSON parser reporting the exact character where the JSON became invalid — common causes are trailing commas, single quotes instead of double quotes, or unquoted keys.