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CSV to XLSX

Convert CSV to XLSX free, in seconds. Paste your data below, press Convert, then copy the result and download a real spreadsheet file. Everything runs in your browser, so nothing is ever uploaded.

CSV input

Paste your CSV below, then press Convert.

The first line is treated as the header row. Quoted fields are respected.

XLSX output

Waiting for CSV input.

Private by design: parsing uses the PapaParse library (loaded once from a CDN); the conversion itself happens locally and your data is never uploaded. The spreadsheet library loads once from a CDN.
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How this conversion works

Paste CSV into the input box and press Convert (or just keep typing, conversion happens as you type). The tool parses it with the PapaParse library, using the first row as column headers, then builds a genuine .xlsx workbook with the SheetJS library and offers it as a download. Parsing uses the PapaParse library (loaded once from a CDN); the conversion itself happens locally and your data is never uploaded.

About the spreadsheet

The SheetJS library builds a real .xlsx workbook entirely in your browser: one sheet named Sheet1, with your column names as the header row and one row per record. Press Download to save converted.xlsx, which opens in Excel, Google Sheets and LibreOffice. The sheet carries your data only, without styling or formulas, and handles thousands of rows comfortably.

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CSV to XLSX FAQs

Why convert CSV to XLSX?
XLSX is the format Excel, Google Sheets and LibreOffice open natively. Converting gives you a genuine spreadsheet file you can email, share and edit, which is far friendlier than raw data for non-technical colleagues.
How is my CSV parsed?
With the PapaParse library: the first line becomes the column headers, quoted fields with embedded commas or line breaks are respected, and empty lines are skipped.
How is the file created?
The SheetJS library builds a real .xlsx workbook entirely in your browser: one sheet with your column names as the header row. Press Download to save converted.xlsx; no server is ever involved.
Are there formatting or size limits?
The sheet contains your data with a header row, without styling or formulas. It handles thousands of rows comfortably, though extremely large exports may take a few seconds to build.
Is my data sent to a server?
No. parsing uses the PapaParse library (loaded once from a CDN); the conversion itself happens locally and your data is never uploaded. The spreadsheet library loads once from a CDN, and your data never leaves your device.
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