CSV to XLSX Converter

Convert CSV files to Excel XLSX format. Fast, secure, and completely client-side conversion with customizable import options.

Overview

This CSV to XLSX converter transforms plain-text CSV files into fully formatted Excel spreadsheets entirely inside your browser — your data never leaves your device. It auto-detects common delimiters (comma, semicolon, tab, pipe) and intelligently preserves data types so numbers stay numbers, dates become real Excel dates, and Unicode text is carried through intact. Whether you are converting a one-off export from a database or batch-preparing reports for colleagues who rely on Excel, the tool gives you a preview of the parsed data before you download, so you can catch any delimiter mismatches before they reach your spreadsheet.

Key Features

  • Convert CSV to XLSX format
  • Customizable CSV delimiters
  • Preview before conversion
  • Preserves data integrity
  • Auto-detect CSV structure

Common Use Cases

  • Database Export Cleanup — Developers and DBAs converting raw SQL or application CSV exports into shareable Excel files without sending sensitive data to a third-party server.
  • Finance & Reporting — Analysts who receive CSV data feeds from accounting or ERP systems and need proper XLSX files with preserved numeric types for Excel formulas and pivot tables.
  • Data Handoff to Non-Technical Teams — Engineers handing off CSV datasets to colleagues who only work in Excel, needing a quick, reliable format switch without spinning up Python or LibreOffice.
  • GDPR-Sensitive Workflows — Teams handling personal data under privacy regulations that prohibit uploading files to external services, using the browser-side conversion to stay compliant.
  • Field Delimiter Troubleshooting — Anyone whose CSV uses semicolons or tabs instead of commas — typically from European locales or TSV exports — who needs to specify the correct delimiter before converting.

How It Works
1

Upload CSV File

Select your CSV file or paste CSV data directly. The tool automatically detects common delimiters or you can specify custom ones.

2

Configure Import Options

Review the detected CSV structure and adjust delimiter settings if needed. Preview how your data will appear in Excel format.

3

Download Excel File

Get your professionally formatted XLSX file ready for Excel, Google Sheets, or other spreadsheet applications with preserved data integrity.

Frequently Asked Questions

What CSV delimiters are supported?
The tool supports comma (,), semicolon (;), tab, pipe (|), and custom delimiters. It can automatically detect the most common delimiter patterns in your CSV file.

How does auto-detection work?
The tool analyzes your CSV file to automatically detect the delimiter, quote characters, and data structure. You can override these settings if the auto-detection isn't perfect.

Are data types preserved during conversion?
Yes, the tool intelligently detects and preserves data types. Numbers remain as numbers, dates are formatted as Excel dates, and text is preserved as text with proper formatting.

Can I handle CSV files with quoted fields?
Yes, the tool properly handles CSV files with quoted fields, escaped quotes, and fields containing the delimiter character. Standard CSV quoting rules are fully supported.

What happens to special characters?
Special characters and Unicode text are properly preserved during conversion. The resulting Excel file maintains full UTF-8 compatibility.

Is there a limit on the number of rows or columns?
The tool can handle files up to 50MB and supports Excel's maximum limits of 1,048,576 rows and 16,384 columns. Large files are processed efficiently.

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