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

How to Compare Two Excel Files for Duplicates

Comparing two Excel files for duplicates might sound like a chore, but it can be tackled easily with a few simple steps. The goal is to spot and highlight identical data, like rows or values, between the two files. Various methods can be employed—ranging from Excel’s built-in features to more advanced techniques using formulas. Ready to become an Excel duplicate-detective? Let’s jump in!

Step-By-Step Tutorial: How to Compare Two Excel Files for Duplicates

In this section, we will walk through the steps to compare two Excel files for duplicates. By the end, you’ll be able to identify and highlight duplicate data easily.

Step 1: Open Both Excel Files

Open the two Excel files you want to compare.
Having both files open is crucial. You need to switch between them to execute commands and compare data effectively. Make sure to save your work frequently to avoid losing any changes.

Step 2: Arrange Data in Columns

Ensure that the data you are comparing is organized in columns in both files.
This will make it easier to apply formulas and filters. Consistent formatting across both files ensures that every data point has a corresponding location for comparison.

Step 3: Use Conditional Formatting

Go to the Home tab, select "Conditional Formatting," and choose "Highlight Cells Rules," then "Duplicate Values."
Conditional Formatting helps to automatically highlight duplicate values. This visual aid makes it easier to spot duplicates without manually scanning through rows and columns.

Step 4: Apply Formulas

Use the VLOOKUP or COUNTIF formulas to find duplicates.
For instance, you can use =VLOOKUP(A2, [OtherWorkbook.xlsx]Sheet1!$A$1:$A$100, 1, FALSE) to check if a value in column A of the first file exists in the second file. Similarly, =COUNTIF([OtherWorkbook.xlsx]Sheet1!$A$1:$A$100, A2) will count occurrences of the value in the other file.

Step 5: Review and Analyze

Examine the highlighted cells or formula results to identify duplicates.
Take your time to review the results carefully. Make sure to cross-check the identified duplicates to confirm their accuracy. Once verified, you can proceed with further actions like deleting or flagging these duplicate values.

After completing these steps, your Excel files will show the duplicate data. You can then take action based on your findings, such as removing the duplicates or using them for further analysis.

Tips for How to Compare Two Excel Files for Duplicates

  • Use Excel’s "View Side by Side" feature to easily compare data between two files.
  • Make sure data types are consistent across both files to avoid errors.
  • Save your work frequently to prevent data loss.
  • Use Excel tables to manage large datasets more efficiently.
  • Keep an original backup of your files before starting the comparison.

Frequently Asked Questions

How do I compare Excel files for duplicates without formulas?

You can use Excel’s "Conditional Formatting" feature to highlight duplicate values without the need for formulas.

Can I automate the process of comparing two Excel files?

Yes, you can write a macro in VBA to automate the comparison process, but it requires some programming knowledge.

What if my data has multiple columns?

Ensure that all columns are aligned correctly and use formulas like VLOOKUP, INDEX, and MATCH to compare multiple columns.

Is there any third-party software for comparing Excel files?

Yes, there are third-party tools like Beyond Compare and WinMerge that can compare Excel files more efficiently.

What happens if the duplicate values are not being detected?

Check for formatting inconsistencies or hidden spaces in your data that might prevent duplicate detection.

Summary of Steps

  1. Open both Excel files.
  2. Arrange data in columns.
  3. Use Conditional Formatting.
  4. Apply Formulas.
  5. Review and Analyze.


Comparing two Excel files for duplicates is no longer a daunting task, thanks to Excel’s powerful features and a few handy formulas. Whether you’re managing inventory, tracking finances, or simply tidying up your data, these steps will make your life easier. By following this guide, you’ll quickly become adept at spotting duplicates, saving you time and effort.

For further reading, consider exploring advanced Excel functions or using VBA for more complex tasks. Remember to always back up your original files before making any changes. Now that you’ve mastered the art of comparing Excel files for duplicates, why not put these skills to use and tackle your next data project with confidence?

Get Our Free Newsletter

How-to guides and tech deals

You may opt out at any time.
Read our Privacy Policy