Free Data Tools

Convert, clean, and reformat CSV and JSON data right in your browser. Because it all runs locally, even sensitive datasets never leave your device.

Frequently asked questions

Is it safe to convert company data — customer lists, exports — online?

Here, yes, and that is the point of running client-side: the CSV is parsed and rewritten inside your browser, so a customer export or financial extract never leaves your machine. With a conventional converter site, that same file lands on someone else's server.

Why does Excel mangle my CSV — dropping leading zeros, turning codes into dates?

Because Excel re-interprets every cell when it opens a raw CSV: '0012' becomes 12, and anything date-like ('MAR1') becomes a date. The data in the file isn't corrupt — it is Excel's type-guessing on open. Converting the CSV to a real .xlsx first, or importing with column types set to Text, avoids the re-guessing.

How large a CSV can these tools handle?

There is no row limit or quota — the practical ceiling is your device's memory, since the parsing happens locally. Files of tens of megabytes are routine on a normal laptop.