Convert CSV to XLSX — free & private
Open any CSV in Excel properly — convert CSV to a real XLSX spreadsheet.
Drop your CSV files, get XLSX back in seconds. No upload — conversion runs inside your browser with WebAssembly.
Start converting CSV → XLSXFree · No sign-up · Batch supported · CSV never leaves your device
How it works
- Choose files — drag & drop or click. Multiple files welcome.
- Click Convert — the converter loads once, then everything runs locally.
- Download — save files one by one or grab them all as a ZIP.
Why ConvertFlow
- Private by design: files are processed 100% locally. Nothing is uploaded, stored or logged.
- No install: works in any modern browser — Windows, Mac, Linux, even phones.
- No tricks: no watermark, no daily cap, no pop-up ads.
- Batch mode: queue many files and download a single ZIP.
FAQ
Is this CSV to XLSX converter really free?
Yes. Every conversion on ConvertFlow runs free in your browser. There is no sign-up, no watermark and no daily limit.
Are my files uploaded to a server?
No. Conversion happens 100% inside your browser using WebAssembly. Your files never leave your device — you can even go offline after the page loads and it still works.
Do I need to install anything?
No installation, no browser extension, no account. Just open the page, drop your files and click Convert.
How many files can I convert at once?
You can queue multiple files and convert them in one batch, then download everything as a single ZIP.
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