JSON Formatter, Validator & JSON ↔ CSV Converter

Format, validate and convert JSON

JSON is the most common format for moving data between web services, but a single missing comma or stray quote makes a whole document unreadable. This tool parses your text with the browser's own strict JSON parser, so what it accepts is what any standards-compliant program will accept. If the text is invalid, it reports the problem together with the line and column so you can jump straight to it.

What each mode does

• Format & Validate re-indents the document with 2 spaces, 4 spaces or tabs, and can sort object keys alphabetically to make two files easier to compare.
• Minify removes all optional whitespace to give the smallest valid text, useful for config values, query strings and API payloads.
• JSON → CSV turns an array of objects into a table. Column names are the union of all keys, nested objects can be flattened into dotted names such as dims.w, and arrays are kept as JSON text inside one cell.
• CSV → JSON reads the first row as field names and returns an array of objects. Quoted fields, embedded commas and line breaks inside quotes are handled, and you can choose a comma, semicolon, tab or pipe delimiter.

Common JSON mistakes

• Trailing commas after the last item are not allowed in JSON.
• Keys and strings must use double quotes; single quotes are invalid.
• Comments are not part of the JSON standard, and values such as undefined or NaN do not exist.

Your input stays on your device: nothing is sent to a server, which makes the tool safe for configuration files and exports that you would rather not paste into an unknown website.

Frequently asked questions

Is my JSON uploaded anywhere? No. Parsing, formatting and conversion all run locally in your browser, and nothing is sent to Figuro or any third party.

Why does my JSON say it is invalid? The most frequent causes are trailing commas, single quotes instead of double quotes, unquoted keys, comments, and missing commas between items. The error message shows the line and column where parsing stopped.

How are nested objects handled when converting JSON to CSV? With flattening on, nested objects become dotted column names like address.city. Arrays are written as JSON text in a single cell because CSV has no native way to represent lists.

Can I convert a CSV that uses semicolons? Yes. Choose the semicolon delimiter before converting. This is common for files exported from spreadsheets set to European regional formats.

Does sorting keys change the meaning of the data? No. JSON objects are unordered collections, so sorting keys only changes how the text looks. Array order is never changed.