CSV to Excel
Convert CSV to a real Excel .xlsx file. Detect or set the delimiter and encoding, choose column types, keep leading zeros and long IDs as text, and name the worksheet.
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About the CSV to Excel
CSV to Excel builds a genuine .xlsx workbook from CSV text in your browser. Upload a file or paste data, let the tool detect the delimiter or pick it yourself, choose the file encoding and say whether the first row is a header.
Every column starts as Text, which keeps values such as 007, phone numbers and 18-digit IDs exactly as written. You can switch columns to Number, Date, Boolean or Auto; any value that cannot be converted safely is listed and kept as text instead of being changed. Text that looks like a formula is always stored as plain text.
How to use
- Upload a CSV file or paste CSV text.
- Check the detected delimiter, encoding and header option.
- Set a type for each column (Text is the safe default).
- Fix or accept any flagged conversions.
- Enter a worksheet name and click Download XLSX.
Key features
- Delimiter detection with manual override.
- Source encodings including UTF-8, UTF-16, Windows-1252 and others.
- Per-column Text, Number, Date, Boolean or Auto types.
- Leading zeros and long identifiers kept as text.
- Invalid conversions flagged, not silently coerced.
- Formula-looking text written as literal text; bold, frozen header row.
Best practices
- Leave ID, phone and postcode columns as Text.
- Choose the date order (day/month or month/day) before converting dates.
- Check the flagged values list before downloading.
Benefits
- Open CSV data in Excel without losing zeros or digits.
- A valid .xlsx file you can share or edit.
- Private: nothing is uploaded.
Frequently asked questions
Why is Text the default type?
Excel automatically converts values like 007 to 7 and long IDs to scientific notation. Keeping columns as text preserves them exactly. Switch a column to Number or Date only when you need calculations.
What happens to values that cannot be converted?
They are listed with their row and column and stored as text, so nothing is lost or silently changed.
Can a CSV cell run a formula in the workbook?
No. Every text cell is written as a literal string; the workbook contains no formulas.
Is my data uploaded?
No. Files and pasted data are processed only in your browser. Nothing is uploaded or stored, and the tool keeps working offline once the page has loaded.