How to Stop Excel from Changing Your CSV Data

Tired of Excel deleting leading zeros or changing IDs into scientific notation? Learn how to prevent auto-formatting destruction.

The Silent Data Killer

One of the most frustrating experiences in data management is watching Excel "helpfully" destroy your data. You open a CSV containing zip codes like 07030, and Excel instantly converts it to the number 7030. Or you have a 16-digit order ID, and Excel changes it to 1.23E+15.

Why Excel Does This

Excel is fundamentally a math tool. When it sees a string of digits, it assumes you want to do math with them. Since leading zeros have no mathematical value, it strips them. Since large numbers take up space, it formats them scientifically.

How to Prevent It

The Import Wizard: Instead of double-clicking the CSV, open Excel empty, go to Data > From Text/CSV, and manually specify that the troublesome columns are "Text" rather than "General".
Use a Raw Data Viewer: If you don't need to do complex math, stop using a math tool to view your data! A dedicated CSV viewer like csv.skin will never alter, strip, or format your raw data. What you see in the raw text file is exactly what renders in the grid.