Keep CSV leading zeros and long IDs as text

Exact limits and boundaries

• UTF-8 only; explicit comma, semicolon, tab, or pipe delimiter.
• Maximum 1 MiB input, 2,000 rows, 64 columns, 32,767 UTF-16 code units per field, and 16 MiB output.
• Core processing is limited to 1.5 seconds; a 1.9-second worker watchdog stops a stalled conversion.
• Dates and amounts remain text. Formula-like strings never become formulas.
• The workbook cannot recover digits already lost before this input.
• The tool writes standard text-cell XLSX output; every spreadsheet application/version and later import workflow is not certified.

When Excel changes a CSV value

CSV fields do not carry spreadsheet cell types. Automatic numeric conversion can remove leading zeros or round sufficiently long IDs. An E-shaped display alone does not prove that digits are lost. Microsoft documents these conversions and an existing native prevention route: import the affected columns explicitly as text.

This alternative creates the whole bounded workbook with every cell typed as text. It does not infer which columns are IDs and which are numbers. Use the original CSV before unwanted conversion; already missing digits cannot be reconstructed.

Worked example: stored text, not a formula or number

This is a fixed illustrative example, not a preview of your data. The download contains every parsed row and field within the stated limits, including the first row; no header is inferred.

Why are amounts and dates also text?

Preserving the original spelling and automatically choosing a numeric/date type are different jobs. This converter chooses preservation for all columns. Arithmetic, date sorting or another downstream import may need your own explicit type conversion later.

How to use the original CSV

1. Choose the original UTF-8 CSV, or enter CSV text. File mode reads its original bytes; pasted line breaks can be normalized by the browser.
2. Select the actual delimiter. Comma, semicolon, tab and pipe are supported without guessing.
3. Create the workbook, then download the complete csv-text.xlsx. Editing input or choosing another delimiter removes the old download.

Malformed quoting, nonrectangular rows, invalid UTF-8 and unsupported or over-limit input stop the conversion rather than truncate or repair your data. Numbers stored as text may have a spreadsheet warning; converting them to numbers can reintroduce rounding or leading-zero changes.

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