How to Remove Duplicates from CSV File on Windows & Mac

But before all, it is necessary to understand that even a single duplicate row in a CSV file can skew the analytics or corrupt data imports in system apps like SQL or Power BI. So, to think of it, what more chaos can duplicates not create? For a brief understanding, see the section below.

Find Duplicates in CSV: Types and Reasons

Find the common non-obvious duplicates that occur in CSV as:

• Mismatched Cases:

  “jerry@sample.com” ≠ “Jerry@sample.com”. So, use Case-Sensitive Filtering or Normalization.

• Whitespaces and Hidden Characters:

  Invisible characters such as \n, \r and trailing spaces make rows appear different. So, normalize before the check or use TRIM().

• Variations in Date Formats:

  “2025/07/04” vs. “04-07-2025” may represent the same entries. So, standardize the formats while cleaning up.

Note: For organizations dealing with financial records, product catalogs, email campaigns, etc., these inconsistencies break systems silently. Generally, it results in non-compliance, duplicate outreach, or misreported figures.

Thatswhy, below mentioned are some crucial reasons to remove duplicates from CSV files:

• Issues with the CRM syncs that cause failed email campaigns and disjointed sales pipelines.
• Inconsistent entries in CSV rows cause mapping issues when integrating data into SQL or BigQuery.
• Duplicate records in items, invoices, or stock data result in false profit or loss projections.
• Failed data migrations as CSV imports into systems like Salesforce, Outlook, or ERP tools often break due to duplicate primary keys or emails.

Which Methods Remove Duplicate Rows in CSV Files?

There is a manual way to eliminate duplicates for free from plain-text spreadsheets CSV. Alternatively, there is a professional tool for the same, which is more secure, faster, and reliable. Both of them are discussed here in a step-by-step instructional guide. Remember that the freeway always comes with some cons, which you will get to know later below.

Manual Method to Remove Duplicates from CSV File

We will discuss the well-known Excel strategy to skip duplicates from CSV. However, it is only best for datasets with under 50,000 rows. The steps are:

1. First, open the .csv file in Microsoft Excel.
2. Then, select your entire dataset or a specific column to eliminate duplicates.
3. Further, browse to the Data tab in the ribbon and click Remove Duplicates.
4. Select the column to remove duplicates from (say, Name, Email, Phone, etc.)
5. Finally, click the OK button to clear all the duplicates.

Excel removes them all and notifies you how many duplicates were found.

Drawbacks of this Method

• Remove duplicates one file at a time, inconvenient for bulk removal.
• Only finds the exact duplicates; partial and mixed-case entries are missed.
• It is a time-consuming and tiring process that requires Excel knowledge as well.

There is another freeway that can only be used if you have specialized technical knowledge or are an IT admin.

Remove Duplicates in CSV File by Command-Lines

It is also case-insensitive and tricky. May not often deliver the required outputs.

Professional Method to Remove Duplicates from CSV File

From the above, it is clear that when working with bulk CSVs, conditional filters, or automation needs, Excel and scripting fall short. So, the SysInfo CSV Duplicate Remover Tool is ideal for bulk de-duplication based on several fields. The tool automatically finds duplicates in CSV. Moreover, it offers batch processing for multiple CSVs and is compatible with Windows 11/10/ and so and all Mac OS versions.

Note: For teams handling marketing lists, HR databases, or financial CSVs regularly, this comprehensive tool prevents hours of manual effort and risky duplicate removals.

How to Easily Remove Duplicate Rows in CSV Files?

1. Download and launch the CSV File Duplicate Remover on any OS.
2. Then, press on Click here to Remove Duplicate Records from CSV file(s).
3. Further, with the Add File button, browse CSV, and click Open to upload.
4. Press Next and filter the records on a different basis as you desire.
5. Additionally, preview the records simultaneously while selecting filters. Tap Next.
6. At last, press Output Path for a location to save new CSV and click Next.

Moreover, you can get a report for the duplicate removal process as well.

Conclusion

To sum up, removing duplicates from CSV isn’t limited to formatting fixes. Instead, it’s a data integrity safeguard for the contacts and other data stored in the CSV. Whether it’s Excel CSV, Google CSV, Outlook CSV, or any other, you can seamlessly remove duplicates from CSV file by following any of the above methods. It helps you get a clean CSV for CRM import, cloud sync, or BI reporting. Also, this ensures trust, accuracy, and smooth operations.

Frequently Asked Questions

About The Author:

Suman Rawat

Suman Rawat is a technical content writer and expert in the fields of email migration, data recovery, and email backup. Her passion for helping people has led her to resolve many user queries related to data conversion and cloud backup.