CSV to JSON Converter
Paste or upload a CSV, get formatted JSON with headers detected.
How to use
- Paste CSV into the input pane, or upload a .csv file up to 5 MB.
- Leave 'First row is headers' on to use column names as JSON keys.
- Turn on 'Convert numbers & booleans' if you want typed values instead of strings.
- Copy the JSON or download it as data.json.
About this tool
This tool converts CSV to JSON in your browser. With headers enabled, each data row becomes a JSON object keyed by the column names in the first row, which is the shape most APIs, scripts, and test fixtures expect. With headers off, each row becomes a plain array. The output is pretty-printed with two-space indentation, ready to paste into code or a request body.
The parser handles the messy parts of real CSV files: quoted fields with embedded commas and line breaks, byte order marks from Excel exports, blank lines, and files that use semicolons, tabs, or pipes instead of commas. The delimiter is detected automatically and shown with the output. Values stay as strings unless you turn on typed conversion, a deliberate default that keeps leading zeros in ZIP codes and IDs intact.
Because everything runs client-side, the tool is safe for exports that contain customer data or anything else you would not upload to an unknown server. Typical uses: feeding spreadsheet data to an API, seeding a database or test suite, or converting a CRM export into something a script can loop over.
Frequently asked questions
+Does my CSV file get uploaded anywhere?
No. Whether you paste text or use the file picker, the file is read and parsed locally by your browser. No data leaves your machine at any point.
+Why are all my numbers wrapped in quotes?
By default every value is kept as a string, which protects things like ZIP codes, phone numbers, and IDs with leading zeros. Turn on 'Convert numbers & booleans' to get real JSON numbers and true/false values instead.
+What delimiters are supported?
Comma, semicolon, tab, and pipe are detected automatically. The delimiter that was detected is shown under the output so you can confirm the guess was right.
+How are malformed rows handled?
The parser is forgiving. Problems like an unclosed quote or a row with the wrong number of fields are reported as warnings above the output, and the rest of the file still converts.
+Can I convert an Excel file (.xlsx)?
Not directly. In Excel, save the sheet as CSV first (File, Save As, CSV), then paste or upload the result here.