JSON Formatter

How to format and validate JSON

1. Paste your JSON. Formatted or minified, valid or not.
2. Format or minify. Choose the indentation, or strip all whitespace.
3. Copy the result. Or download it as a .json file.

About JSON Formatter

JSON arrives from an API as one enormous line with no whitespace, which is correct for transmission and unreadable for humans. Formatting adds indentation and line breaks so the structure becomes visible: you can see what is nested inside what, which is usually the actual question when someone is staring at an API response.

Minifying goes the other way, stripping every unnecessary character. That matters when the JSON is going into a config file with a size constraint, being embedded in a page, or transmitted somewhere that charges by the byte. The data is identical either way; only the whitespace changes, and no parser cares.

Validation is the part people come for most often. A single misplaced comma makes an entire file invalid, and the browser's own error messages are famously unhelpful. This shows the parser's error along with the position, so you can find the problem rather than reading the whole file. The usual culprits are consistent: a trailing comma after the last item in an array or object, single quotes instead of double, unquoted keys, and an unescaped quote inside a string.

Worth knowing that JSON is stricter than JavaScript object syntax, which is what trips people up most. Valid JavaScript is frequently invalid JSON: comments are not allowed, keys must be in double quotes, trailing commas are forbidden, and single-quoted strings are not permitted. If something looks fine to you and the parser disagrees, it is almost always one of those four.

JSON Formatter FAQ