JSON to CSV Converter

A JSON to CSV converter takes a JSON array of objects and rewrites it as comma-separated values, with one column per property and one row per object. Paste the response from an API, a database query, or an exported document and get back a file you can open directly in Excel, Google Sheets, or Numbers. The property names become the header row and every object becomes a data row underneath.

Here is what this online JSON to CSV converter does with an uneven input. Paste [{"id":1,"name":"Lovelace, Ada","address":{"city":"London"}},{"id":2,"name":"Grace Hopper","tags":["navy","cobol"]}] and click Convert to CSV. The header comes out as id,name,address.city,tags: the nested city becomes its own column, and tags, which only the second object has, is added at the end. The first row is 1,"Lovelace, Ada",London, with the name quoted because it contains a comma, and the second row keeps the tags array as JSON in one cell with its quotes doubled.

JSON is the format APIs and JavaScript programs speak, but spreadsheets, business intelligence tools, and non-technical colleagues need tabular CSV. Doing the conversion by hand means picking the columns, handling records that are missing a field, and quoting any value that contains a comma or a line break. This tool builds the header from the union of every key across all objects, so rows with different shapes still line up, and it escapes fields using the RFC 4180 rules so a value like a full address survives the trip into a spreadsheet intact. Nested objects can be flattened into dot-notation columns such as address.city, and arrays can be joined or kept as JSON in a single cell.

Everything runs in your browser with no libraries and no server, so the JSON you paste - which often holds API payloads, user records, or internal data - is never uploaded or stored. The converter works offline once loaded, lets you choose the delimiter and line ending, and warns you when an item is not an object or when the input is a single object rather than an array.