Excel Data Analyzer

This is a solid utility for auditing Excel files before you start working with the data. It generates markdown reports with data type detection, missing value percentages, format inconsistencies like mixed types or whitespace issues, and statistical summaries including outlier detection. The quality scoring system (0-100) helps prioritize what to fix first, and it handles multi-sheet workbooks without choking. Runs on Bun with the xlsx library, so it's reasonably fast even on larger files. The main caveat is it only analyzes and reports, it doesn't clean anything for you. Good for that initial "what am I dealing with here" pass when someone hands you a messy spreadsheet.