Use the formula =IF(A2<>B2, "Difference", "") in an adjacent column and drag it down. All rows with differences will be marked.

For visual inspection, select both columns, choose "Conditional Formatting" → "Highlight Cells Rules" → "Duplicate Values" → "Unique". Excel will highlight cells without a pair.

This method is part of a powerful conditional formatting tool. With it, you can, for example, make Excel highlight debts and overdue items based on specified conditions.

🔗 Source: excel.rf