CSV → XLSX
Convert CSV to Excel – server-side
Why CSV → XLSX?
Convert CSV files to Excel – with formatting and formulas, deleted immediately.
Frequently Asked Questions
Why convert CSV to XLSX?
XLSX offers formatting, formulas, and multiple sheets – more features than CSV.
Are my files safe?
Yes. Files are processed and deleted immediately.
About XLSX
XLSX (Office Open XML Spreadsheet) was introduced by Microsoft in 2007 as the successor to XLS and is part of the ISO 29500 standard. XLSX is based on XML and stored as a ZIP archive containing worksheets, formulas, cell formatting, charts, and macros as XLSM variant. The format supports over one million rows and 16,384 columns per sheet, significantly more than the legacy XLS format with its 65,536 row limit. LibreOffice Calc and Google Sheets can open XLSX files, though complex Excel functions and VBA macros may not be fully compatible. XLSX has replaced the binary XLS format and is the standard for spreadsheets in business and organizations worldwide. The XML structure enables automated data extraction and programmatic processing of calculations. For data export without formatting, CSV is the simpler alternative; for distribution as a document, converting to PDF. XLSX also supports conditional formatting, pivot tables, data validation, and external data connections.
About CSV
CSV (Comma-Separated Values) is a text format for tabular data that has been used since the 1970s and was formally described as RFC 4180 in 2005. Each line represents a record, with values separated by delimiters - usually commas, or semicolons in European locales. CSV is supported by all spreadsheet programs and databases and is the simplest format for data exchange between different systems. The format has no standard encoding, no type system, and no schema definition, which frequently leads to problems with decimal separators, character sets, and date formats across different regions. TSV (Tab-Separated Values) is a widespread variant using tabs instead of commas. For structured data with nested structures, JSON is preferable; for spreadsheets, XLSX. However, CSV remains the de facto standard for data export and import due to its universal compatibility and simplicity. Every programming language offers CSV parsers, and databases can import and export CSV directly.
Why convert CSV → XLSX?
CSV (Comma-Separated Values) is the simplest tabular format — plain text with delimiters. It has no formatting, no formulas, no charts, and is error-prone with decimal numbers and date formats (comma vs. period, DD.MM vs. MM/DD). Converting to XLSX is needed when you want to present data more structurally (XLSX with formulas and formatting), need a format better processed by web APIs and databases (JSON), or must create professional reports (PDF). XLSX is Microsoft Excel's spreadsheet format with formulas, charts, and conditional formatting for professional data processing.