Duplicates in a spreadsheet might seem harmless—until they throw off your totals, mess up your reports, or confuse your team. Whether you’re cleaning up a contact list, filtering survey responses, or managing product inventory, duplicate rows can create a lot of problems. Thankfully, Google Sheets offers simple, beginner-friendly ways to spot and remove duplicates with just a few clicks.
In this guide, you’ll learn how to find and delete duplicate rows in Google Sheets using built-in tools and formulas. Whether you’re managing small datasets or large spreadsheets, these tips will save you time, reduce errors, and keep your data accurate.
Why Duplicate Rows Happen—and Why They Matter
Duplicates usually sneak into spreadsheets during manual entry, copy-paste errors, or when importing data from different sources. And while one or two extras might seem harmless, they can:
- Skew totals in financial or inventory reports
- Cause double emails in mailing lists
- Lead to miscommunication within teams
That’s why it’s essential to clean them up regularly—especially when your sheet is shared or growing quickly.
Built-In Method: Use Google Sheets’ “Remove Duplicates” Tool
The easiest way to delete duplicate rows is by using the built-in tool:
- Select the range of data you want to check for duplicates.
- Go to Data → Data cleanup → Remove duplicates.
- A pop-up will appear. Check the box that says “Data has header row” (if your data has headers).
- Select which columns to consider when finding duplicates. For full-row matches, leave all columns checked.
- Click Remove duplicates.
Google Sheets will show how many duplicates were found and removed. It’s that easy!
Real-Life Example: Cleaning a Contact List
Let’s say you’ve imported multiple client contact lists and ended up with duplicates. Here’s how your raw data might look:
| Name | Company | |
|---|---|---|
| Alex Green | alex@email.com | GreenTech |
| Sara Kim | sara@email.com | HealthCorp |
| Alex Green | alex@email.com | GreenTech |
Using the Remove Duplicates tool on all columns will leave only one entry for Alex Green, cleaning your list instantly.
Formula Method: Highlight or Flag Duplicates First
If you’re not ready to delete rows immediately, try highlighting or flagging them using a formula. Here’s a great one for identifying duplicate values in a specific column (like emails):
=COUNTIF(B:B, B2) > 1
Use this in a new column to return TRUE for any value that appears more than once. You can then filter or sort your sheet to deal with those rows manually.
Step-by-Step for Highlighting Duplicate Emails
- Insert a new column titled “Duplicate?”
- In the first row under it, enter:
=COUNTIF(B:B, B2) > 1 - Drag the formula down to apply it to the whole column.
- Rows with “TRUE” are duplicates.
Using Conditional Formatting to Highlight Duplicates
If you prefer to see duplicates without removing them, try conditional formatting:
- Select the column you want to check (e.g., Email column).
- Click Format → Conditional formatting.
- Under “Format cells if,” choose “Custom formula is.”
- Enter:
=COUNTIF(B:B, B1) > 1 - Choose a highlight color and click Done.
All duplicate values in the column will now be highlighted for easy review.
Best Practices for Duplicate Cleanup
- Always back up your data before removing duplicates—just in case.
- Use formulas first if you want more control over what gets removed.
- Make sure you select all relevant columns when using the built-in tool to avoid false positives.
- Use filters to sort and review duplicates before deleting them.
Quick Cheat Sheet: Finding & Removing Duplicates
| Method | Use Case | Steps |
|---|---|---|
| Remove Duplicates Tool | Instant full-row removal | Data → Data cleanup → Remove duplicates |
| COUNTIF Formula | Flag duplicates in a column | =COUNTIF(B:B, B2) > 1 |
| Conditional Formatting | Visually highlight duplicates | Format → Conditional formatting → Custom formula |
Removing duplicate rows in Google Sheets doesn’t have to be a tedious task. Whether you use the built-in tool, formulas, or visual cues, keeping your data clean and accurate is just a few steps away. Especially if you’re working with shared files or large datasets, learning how to manage duplicates is a simple skill that makes a big difference.
Next time you’re cleaning up your spreadsheet, use one of these methods—and enjoy a faster, cleaner workflow without the duplicate drama.