CSV to Excel
Convert CSV data to Excel spreadsheet format
Packing a CSV into a real workbook
Paste your CSV into the box and the tool writes a single-sheet .xlsx from it. Two parts of that process cause most of the surprises: how each cell gets its type, and the fact that the parser splits on commas only.
How a cell gets its type
The decision happens per cell, not per column. A value becomes a number only when converting it and printing it back yields the exact same text:
- 95000 round-trips exactly, so it lands in Excel as a number you can sum.
- 007 would print back as 7, so it stays text and keeps its leading zeros. Phone numbers and zip codes survive the same way.
- 1e5 and other scientific notation stay text rather than silently becoming 100000.
- Dates stay text. The tool does no date parsing, so 2024-01-15 arrives as a string you can convert inside Excel if you need a real date.
Because the check is per cell, a column can mix numeric and text cells without producing errors. To keep numbers numeric, strip thousand separators and currency symbols from the source first, since 1,234.50 fails the round-trip and stays text.
Commas only
The parser splits fields on commas, full stop. European exports often use semicolons, since comma is their decimal mark, and database dumps often use tabs. Paste one of those and the workbook lands as one giant column. Open the source in a text editor, replace the semicolons or tabs with commas (quote any values that already contain commas), and convert again.
Conversion questions
- How does the tool handle quotes and commas inside values?
- Wrap the value in double quotes and it can contain commas, line breaks, and even doubled quotes ("" becomes a single " in the cell). The parser reads quoted fields across line breaks, so multi-line addresses survive intact.
- Can I get multiple sheets from one CSV?
- No, a CSV is one table by definition. Convert each CSV on its own, then combine the files in Excel with Move or Copy Sheet.
- What about character encoding?
- You paste text rather than upload a file, so your editor or clipboard has already decoded it. If accented characters look right in the input box, they come out right in the workbook.
- What happens when the input is malformed?
- Two guards run before download. If a quote (") opens and never closes, the tool stops and tells you the line where it opened, since an unterminated quote would swallow the rest of the file into one cell. And any single cell longer than 32,767 characters, which is Excel's hard per-cell limit, gets shortened to fit with a warning so the conversion never fails outright.