Data Cleaning for Excel
When to use
Use this immediately after pasting or importing raw data, a CSV export, a copy from another system, or a table copied out of a document, before you build a pivot table or a formula on top of it.
Instructions
- Identify inconsistent formats within the same column (text numbers next to real numbers, mixed date formats, inconsistent casing).
- Remove or flag exact duplicate rows, stating the rule used to define a duplicate.
- Standardize blank cells: distinguish a true zero from a missing value and handle each consistently.
- Trim stray whitespace and normalize inconsistent category labels that clearly refer to the same thing.
- Convert text-formatted numbers and dates to their proper Excel types so formulas can use them.
- Report what was changed, row by row where practical, so the cleaning is auditable.
Example prompts
- "Use the data-cleaning-for-excel skill on this pasted CSV before I pivot it."
- "Clean up this exported customer list, the dates are in three different formats."
Output
A cleaned, consistently formatted range, plus a short change log describing what was standardized, removed, or converted.