JSON Formatter

Format, validate, minify and repair JSON online

JSON that comes out of a log, a web service response or a config file is often one long line, or almost valid but not quite. The JSON Formatter does the four jobs that come up every day: it validates the text and tells you the exact line and column of any mistake, pretty-prints it with 2 spaces, 4 spaces or tabs, minifies it for transmission, and optionally sorts the keys so two files can be compared by eye.

Paste the JSON or drop a .json file. When repair is on, the most common paste mistakes are fixed before validation: comments, trailing commas, single-quoted strings, unquoted keys, capitalised True, False and None, NaN and Infinity, a stray byte-order mark and Markdown code fences around the text. The result tells you when a repair was applied, so you know the input was not strict JSON. Nothing else is changed: numbers keep their precision, key order is preserved unless you ask for sorting, and Unicode is written as it is rather than escaped.

The formatted file is downloaded with a name that says what happened to it. The same validator runs inside every JSON tool on this site, so a file that passes here converts everywhere. For a structural comparison of two files use Compare JSON, and to move the data into a spreadsheet use JSON to Excel or JSON to CSV.