Is my file uploaded when converting XLSX to CSV?

No. The conversion runs entirely in your browser. The file never leaves your device, there is no server to upload to, and the page works offline once loaded.

Is XLSX to CSV conversion free?

Yes, with no account, no watermark and no file limit per day. frogConvert is open source and there is no server cost to recover, because your device does the work.

How large a file can I convert?

Up to 2 GB for a single file, 500 MB total per batch, and 300 files at once. The practical limit is your device's memory, since everything is processed locally.

Convert XLSX to CSV

Exports spreadsheet cell values as comma-separated text.

Convert XLSX to CSV →

Runs on: a 2-step chain of local converters
Steps: 2 steps, chained automatically
Input: .xlsx · application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
Output: .csv · text/csv
Uploads: None. The file never leaves your device.

What to expect

CSV holds one table, so only a single sheet is exported. Formulas become their computed values, and all formatting, charts and multiple sheets are lost.

Why convert XLSX without uploading

Most online converters take your file, send it to their servers, convert it there and hand back a download link. That means your document sits on someone else's disk, subject to their retention policy and their breaches. It also means you cannot use them offline, and cannot use them at all for anything confidential.

frogConvert does the conversion in the page itself, with the conversion engines compiled to WebAssembly. There is no upload step because there is no server. You can disconnect from the network and it still works.

About the formats

XLSX

Microsoft Excel's format: multiple sheets, formulas, cell formatting and charts in a ZIP of XML. Only the cell values survive a conversion to a flat tabular format. More about XLSX files.

CSV

Comma-separated values: one table, one type, no formatting and no formulas. Its simplicity is the reason it is universal and the reason it loses everything a spreadsheet adds. More about CSV files.

Common questions

Is my file uploaded when converting XLSX to CSV?: No. The conversion runs entirely in your browser. The file never leaves your device, there is no server to upload to, and the page works offline once loaded.
Is XLSX to CSV conversion free?: Yes, with no account, no watermark and no file limit per day. frogConvert is open source and there is no server cost to recover, because your device does the work.
How large a file can I convert?: Up to 2 GB for a single file, 500 MB total per batch, and 300 files at once. The practical limit is your device's memory, since everything is processed locally.
What is lost converting XLSX to CSV?: CSV holds one table, so only a single sheet is exported. Formulas become their computed values, and all formatting, charts and multiple sheets are lost.