Preserve Leading Zeros in CSV

Instructions

1. Paste a table with a header, choose identifier columns and a minimum width, then pad and download.
2. In Excel use Data → From Text/CSV and set these columns to Text before loading.

Understanding your result

With minimum width 5, sample ID 12 becomes 00012 and 007 becomes 00007. These are identifier strings, not calculations. The file can contain the correct zeros even when Excel subsequently hides or removes them during automatic import.

What to do if you have a problem

If zeros disappear, import the downloaded CSV with those columns set to Text. If an ID has already lost digits or zeros in your source, recover it from the original system first. Increasing the width only adds padding; it cannot recover missing information.

What to know before using the result

CSV cannot force an Excel text data type. Directly opening the downloaded CSV can remove leading zeros. Existing longer identifiers remain intact; nonblank identifiers must contain digits only. Width is 1–100 characters. This tool does not add formulas or reconstruct digits already lost in Excel. Maximum 2 MB and 20,000 rows.

These tools work with pasted text or supported CSV files rather than Excel workbook files. CSV exports contain values and do not preserve workbook formatting, formulas or multiple worksheets. Formula builders produce formula text to use in Excel. Data processing runs in the browser tool.

Try an example

ID,Name
12,Ada
007,Sam

Summary

Import the padded identifier columns as Text in Excel so the zeros remain part of each ID.