CSV to XLSX

How this reads your output

The CSV is parsed with its delimiter inferred, then written as a workbook. Before that happens, every column is checked for values a spreadsheet would reinterpret, and they are named with what they would become. That check is the substance of the tool: a converted file with a postcode column reading 1234 instead of 01234 opens perfectly, shows the right columns, and is wrong. Keeping every value as text is on by default and forces each cell to a string type in the written file, which is what stops the writer re-guessing on the way out.

What the results mean

Values kept as text

On by default. Every cell is written as a string, so nothing is reinterpreted.

Leading zeros

Data rather than formatting. Postcodes and part numbers depend on them and cannot be recovered.

Date coercion

SEPT1 and MARCH1 become dates. Real month names only — a part code like SKU123 is left alone.

Fifteen digits

All a spreadsheet carries. Longer identifiers lose their final digits silently.

Common problems and fixes

My postcodes lost their leading zeros

Turn on keeping values as text. Once converted without it the zeros are gone from the file and cannot be restored.

A product code turned into a date

Same fix. Text mode stops the reinterpretation; without it the original string is not stored anywhere in the file.

Long ID numbers end in zeros

Fifteen significant digits is the spreadsheet limit. Text mode keeps them intact, since a string has no such limit.

Frequently asked questions

More in Data

• XLSX to CSVConvert a spreadsheet to CSV, one file per sheet, with what gets lost stated first.
• CSV ViewerView a CSV as a table — and find the rows that do not line up.
• JSON to XLSXTurn JSON into a workbook, with nested objects flattened rather than stringified.