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CSV to XLSX
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Supported formats: .csv,.xlsx,.xls,.xlsm,.xlsb,.tsv
AboutCSV to XLSX
Securely convert CSV files to native Excel XLSX format with correct formatting, data types, and UTF-8 encoding. Free online CSV to Excel converter that handles large files, preserves special characters, and works without uploading data to external servers.Category: Conversion & ExportPreparing raw data for management reportsFixing CSV opening errors in ExcelConverting huge CSVs to readable spreadsheets
The CSV to XLSX tool is compatible with:Microsoft Office 365SharePointFinancial Reporting.Pair with the Multiway Converter when the same dataset also needs to go out as JSON or TSV, or with Smart Merge first if you need to combine several CSVs into one workbook before converting.A plain CSV opened directly in Excel often mangles leading zeros, dates, and accented characters because Excel guesses the column types on open. This tool builds a real XLSX workbook instead, assigning correct cell types (text, number, date) up front so codes like "007" or IDs like "01-234" stay intact. It's the fix for the classic "Excel changed my data" complaint that hits anyone importing CSV exports into spreadsheets.
Frequently Asked Questions:
Will special characters and encoding survive the conversion?
Yes, it preserves UTF-8 encoding and special characters when generating the native XLSX file.
Does this work for very large CSV files?
Yes, it's built to handle large files without needing to upload them to an external server.
Aimed at analysts and accountants who are tired of re-typing IDs Excel silently stripped of leading zeros.