How to Compare Two Excel Sheets for Duplicates: A Step-by-Step Guide

Comparing two Excel sheets for duplicates can be a headache, but it doesn’t have to be. With the right tools and know-how, you can quickly find duplicate data and clean up your spreadsheets. In just a few steps, you can compare two Excel sheets, identify duplicates, and decide what to do with them. Let’s dive into the nitty-gritty of how to get this done.

Step by Step Tutorial on Comparing Two Excel Sheets for Duplicates

Before we get into the steps, knowing what these steps will accomplish is important. By following these instructions, you’ll learn how to use Excel’s built-in features to compare two sheets and highlight or remove duplicate entries.

Step 1: Open both Excel sheets you want to compare

This step involves opening the two Excel workbooks that you want to compare for duplicates.

Once you have both Excel sheets open, make sure you can easily switch between the two. You might want to arrange the windows side by side for easier comparison.

Step 2: Use the ‘Conditional Formatting’ feature

In this step, you’ll use Excel’s ‘Conditional Formatting’ feature to highlight duplicates.

Select the range of cells you want to check for duplicates on the first sheet. Then, go to the Home tab, click on ‘Conditional Formatting’, then ‘Highlight Cell Rules’, and choose ‘Duplicate Values’. Excel will highlight any duplicates in the selected range of cells.

Step 3: Repeat the ‘Conditional Formatting’ on the second sheet

Now, do the same thing on the second Excel sheet.

Again, select the range of cells then apply the ‘Conditional Formatting’ feature to highlight duplicates. Be sure to use the same criteria for highlighting so you can have a consistent comparison.

Step 4: Compare the highlighted duplicates across both sheets

With duplicates highlighted, you can now start comparing the two sheets.

Look through the highlighted cells on each sheet and compare them to the other sheet. You can manually check for duplicates or use the ‘Find and Select’ feature in Excel to jump straight to highlighted cells.

Step 5: Decide what to do with the duplicates

Once you’ve identified duplicates, decide how to handle them.

You might want to delete duplicates, merge data, or take some other action. Remember, always make sure you’re not removing any critical data before deleting anything.

After completing these steps, you should have a clear view of where the duplicates are in your Excel sheets. You’ll be able to decide on the best course of action to clean up your data.

Tips for Comparing Two Excel Sheets for Duplicates

  • Always back up your Excel files before making any changes. You don’t want to accidentally lose important data.
  • Use tables instead of ranges to make your Excel sheets easier to manage and compare.
  • Consider using Excel’s ‘Remove Duplicates’ feature if you want to quickly delete duplicate entries.
  • If you’re working with large datasets, consider using Excel’s ‘Advanced Filter’ to manage and analyze data more efficiently.
  • If you need to compare more than two Excel sheets, consider consolidating them into one master sheet first for easier comparison.

Frequently Asked Questions

Can I compare more than two Excel sheets at once for duplicates?

Yes, you can compare more than two Excel sheets for duplicates, but it’s more complex and requires consolidating the sheets or using a specialized tool.

Do I need any special software to compare Excel sheets for duplicates?

No, Excel’s built-in features are usually sufficient for comparing sheets for duplicates. However, for more complex tasks, specialized software might be helpful.

Will ‘Conditional Formatting’ change my data in any way?

No, ‘Conditional Formatting’ will not change your data. It simply highlights cells based on your criteria and can be easily removed.

Can I automatically delete duplicates in Excel?

Yes, Excel has a ‘Remove Duplicates’ feature that allows you to automatically delete duplicates. However, use it cautiously and ensure you don’t delete any important data.

How can I prevent duplicates in Excel in the first place?

You can prevent duplicates by using data validation rules, which help ensure that only unique data is entered into your Excel sheets.


  1. Open both Excel sheets.
  2. Use ‘Conditional Formatting’ on the first sheet.
  3. Apply ‘Conditional Formatting’ on the second sheet.
  4. Compare the highlighted duplicates.
  5. Decide on the action for duplicates.


Comparing two Excel sheets for duplicates might seem daunting at first, but it’s quite straightforward with a little practice. The key is to use Excel’s powerful ‘Conditional Formatting’ feature and to approach the task methodically. Remember to always back up your data before making any changes, and don’t be afraid to use additional features like ‘Remove Duplicates’ or ‘Advanced Filter’ for larger datasets. With these tips and steps in mind, you’ll be an Excel comparison whiz in no time. Keep experimenting with different Excel features to find the best workflow for your needs, and never let duplicates get the better of your spreadsheets again!

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