CSV to JSON Converter

Convert between CSV and JSON

Spreadsheets speak CSV; web APIs speak JSON. This converter goes both ways — turning CSV rows into a clean JSON array of objects, or flattening a JSON array back into CSV. Everything runs in your browser, so your data never leaves your device.

How it works

• CSV → JSON — the first row becomes the object keys; each later row becomes one object. Values that look like numbers are converted automatically.
• JSON → CSV — the object keys become the header row, and every object becomes a line, with quoting added wherever a value contains a comma, quote, or newline.

FAQ

Does it handle quoted fields and commas inside values?

Yes — the parser follows the common RFC 4180 rules, so quoted fields, escaped quotes (""), and embedded commas and newlines are preserved correctly in both directions.

Is my data uploaded to a server?

No. The conversion runs entirely in your browser using JavaScript, so your CSV or JSON never leaves your device. That makes it safe for sensitive data like exports of customer records or internal reports.

What JSON shape does it expect for JSON to CSV?

An array of flat objects, where each object becomes one row and the keys become column headers. Deeply nested objects or arrays inside values don't map cleanly to a flat table, so flatten them first for best results.

How are numbers and booleans handled?

Going from CSV to JSON, values that look like numbers are converted to numeric types automatically rather than left as strings. If you need a value kept as text, such as a ZIP code with a leading zero, be aware it may be read as a number.

Is the converter free, and does it work on mobile?

Yes, it is completely free with no sign-up or file-size paywall, and it works in any modern browser on phones, tablets, and desktops.