text2csv.com

CSV to XLSX (Excel) Converter — Free Online Tool

Turn any CSV into a proper Excel workbook. Numbers stay as numbers, leading zeros preserved as text, no upload required.

100% privateNo signupRFC 4180
Drop a file, paste, or type. Processed locally — never uploaded.

Settings

Max 31 characters (Excel limit).

Excel file will be ready here

Paste CSV or drop a file, then click Convert

How it works

4 steps. Everything runs in your browser.

1

Paste CSV

Paste your CSV data, drop a .csv file, or type directly.

2

Configure

Pick the delimiter (comma, semicolon, tab, pipe), set a sheet name, toggle header detection.

3

Convert

SheetJS builds a proper .xlsx workbook locally — numbers stay numbers, dates stay dates.

4

Download

Get the .xlsx file ready to open in Excel, Google Sheets, Numbers, or LibreOffice Calc.

Why not just rename the .csv extension to .xlsx?

Renaming doesn't work — CSV is plain text, XLSX is a zipped XML archive. Excel will show an error and refuse to open a renamed file. You need a real conversion that builds a valid XLSX structure with cell types, sheet metadata, and shared strings.

This tool uses SheetJS to construct a native XLSX workbook from your CSV input. The output is a real .xlsx file Excel opens cleanly, with proper numeric typing for cells that look like numbers, and text typing preserved for values with leading zeros (ZIP codes, account numbers, SKUs).

The leading-zero problem (and why this tool fixes it)

When you open a CSV directly in Excel, the cell "012345" (e.g., a ZIP code) is automatically converted to the number 12345 — the leading zero is silently lost. This tool detects values that start with a zero and stores them as text in the XLSX, so they display exactly as they appear in the CSV. The same applies to long numbers that would otherwise become scientific notation.

Common use cases

Database export
PostgreSQL/MySQL → CSV → XLSX for ad-hoc analysis in Excel.
API output to spreadsheet
Convert REST API CSV downloads to a workbook for finance teams.
Bulk delivery
Send CSV reports to non-technical recipients as familiar .xlsx attachments.
Preserving formatting
Avoid Excel's auto-format mangling by converting first.
Multi-CSV combine
Generate multiple sheets by converting CSVs one at a time with unique sheet names.
Pipe-delimited data
Convert legacy mainframe/EDI exports (pipe-delimited) to Excel-ready XLSX.

Why use our CSV to XLSX converter?

100% private

CSV parsed and XLSX built entirely in the browser. No upload, no tracking.

Preserves types

Numbers store as numbers. Leading zeros stay as text. No Excel auto-format surprises.

Custom sheet name

Name the sheet anything you want (up to Excel's 31-char limit).

Related tools

More free converters from text2csv.com

XLSX to CSV →

Reverse direction — extract CSV from an Excel workbook.

JSON to CSV →

Convert JSON data first if your source is API output.

Text to CSV →

General-purpose converter for any tabular text.

Frequently asked questions