About this conversion
Convert CSV to XLSX to open data in Excel with proper formatting and types. CSV is portable but flat — Excel's XLSX format adds typed cells, formatting, formulas, and the ability to use Excel features like pivot tables and named ranges on top of your data.
When this conversion is useful
- Sharing CSV data with someone who'll work in Excel and wants types preserved
- Producing an XLSX file from a CSV export for downstream Excel-based reports
- Preparing data for users who'd struggle with raw CSVs but are fluent in Excel
- Adding formatting, formulas, or styling to CSV-sourced data in Excel
Quality and tradeoffs
Numbers are detected and stored as Excel numbers (no quote prefix surprises). Dates and booleans are detected when their format is unambiguous. Long numeric strings (IDs, phone numbers) may be auto-converted to numbers — prefix with apostrophe in the source if you need to preserve them as text.
Frequently asked questions
Why do my long numbers (IDs, phone numbers) display in scientific notation?
Excel auto-converts long numeric strings to numbers, which trip its display threshold. Format the column as Text in the XLSX after opening, or prefix the source CSV cell with an apostrophe to force text.
Are dates parsed automatically?
Yes, when the date format is unambiguous (ISO 8601, common locale formats). Ambiguous formats like `01/02/2024` may be interpreted as US (Jan 2) or EU (Feb 1) — explicit ISO format is safest.
Will my CSV's UTF-8 characters survive the conversion?
Yes. The XLSX output uses Unicode internally, so accented characters, emoji, and non-Latin scripts come through cleanly without the BOM-encoding issues that plague CSV in Excel.