Conversion runs in your browser. Nothing is uploaded.
A two-way converter between JSON and CSV for when you need to open a JSON API response in a spreadsheet, or turn a CSV pasted from Excel into a JSON array your code can use. Paste JSON (an array of objects, or a single object) or CSV into the top box, pick the direction (JSON→CSV or CSV→JSON), and the result appears instantly in the box below. For JSON→CSV it takes the union of keys across all objects, in first-seen order, to build the header row, so columns stay aligned even when some rows are missing keys. Nested objects and arrays are written into the cell as a JSON string, and any value containing the delimiter, a double quote, or a newline is wrapped in double quotes with inner `"` escaped as `""`, following RFC 4180. For CSV→JSON it correctly parses quoted cells, embedded newlines, and escaped quotes, then treats the first row as headers and turns each row into an object. Turn on "Type values" to output strings like `123`, `-4.5`, `true`, `false`, and `null` as numbers, booleans, and null; turn it off to keep every value as a string. The delimiter can be comma, tab (TSV), or semicolon (the default in some Excel locales). Importantly, the data you enter is never uploaded, stored, or sent to a server — all processing happens with JavaScript entirely inside your browser, so internal rosters, sales figures, and unreleased API samples you can't share stay on your device. Note that this tool is optimized for converting between an array of objects and header-based tabular CSV; it does not flatten deeply nested structures into columns or infer multi-sheet or type schemas.
How to use
- Paste JSON (an array of objects) or CSV into the top box.
- Choose the direction (JSON→CSV or CSV→JSON) and the delimiter.
- The converted result appears in the box below. Use "Copy" to grab it. Your input is never sent anywhere.
FAQ
Is the data I enter uploaded anywhere?
No. All conversion happens with JavaScript inside your browser, and the data is never uploaded, stored, or sent to a server. Internal rosters and unreleased API samples you can't share stay entirely on your device.
Can it convert JSON where rows have different keys?
Yes. For JSON→CSV it builds headers from the union of all object keys in first-seen order. A key missing from an object simply leaves that cell empty, and columns stay aligned.
How are values containing the delimiter or newlines handled?
Following RFC 4180, any value containing the delimiter, a double quote, or a newline is wrapped in double quotes and inner quotes are doubled to escape them. The CSV→JSON side parses this format correctly as well.
What does "Type values" do?
For CSV→JSON, it outputs strings like `123`, `true`, and `null` as numbers, booleans, and null. Turn it off to keep every value as a string — useful when you need to preserve postal codes or leading zeros.
Does it support TSV (tab) or semicolon delimiters?
Yes. You can choose comma, tab, or semicolon as the delimiter. Tab gives you TSV, and semicolon is the default that some Excel locales expect.