Merge CSV Files and Remove Duplicates
Merge two or more CSV exports into one file. Columns line up by their header, even when one file says E-Mail and the other email, and duplicates go by email or any column you pick. Free, in your browser, nothing uploaded.
Your CSV Files
The merger needs JavaScript.
One List From Many Exports
Webinar leads, a trade-show list and a CRM export rarely share a column order. The merger reads each file’s header and puts every value under the right column; columns only one file has stay, empty for the rest.
Duplicates are found by the column you choose, ignoring case and spaces at the ends: Ben.Okafor@Example.com and ben.okafor@example.com are one person.
Email = E-Mail
First name = first_name
Company → file 1 only
Country → file 2 onlyTry a Real Merge
Each loads two small files into the merger.
- Example
Webinar and Trade-Show Leads
Two lists with different column names and order. Two people are on both, once with capitals and once with a trailing space.
- 2files
- 6rows in
- 2duplicates removed
- Columns
Different Column Order
Same columns, other order: values still land in the right place.
- Columns
A Column Only One File Has
Country exists in one file; the merged file keeps it, empty for the other rows.
- Duplicates
Same Email, Other Spelling
Capitals and spaces don’t make a new person.
- Duplicates
Dedupe by Company Instead
Pick any column as the key, here the company.
From Several Exports to One Import
Four steps to a list Account Engagement (Pardot) or Salesforce can take.
- 1
Add Your Files
Add CSV Files reads them in your browser; add more any time.
- 2
Choose the Key
The email column is picked if there is one. Pick any column, or keep every row.
- 3
First or Last
Keep the first row of each duplicate, or the last, for example the newest export.
- 4
Download and Check
Download the merged CSV and open it in the CSV viewer before you import.
Duplicates Before a Pardot Import
Why a merged, deduplicated file imports cleaner.
- 1Row kept per duplicate
- 50MB per file, read in your browser
- 0Files uploaded
- Matching by email. Pardot matches imported prospects by email or by CRM ID, so two rows with one email go to the same prospect. Decide which row counts before the import.
- Case and spaces. The merger compares keys trimmed and case-insensitive, the way two people would read them.
- Empty keys. Rows without a value in the key column are kept, never merged with each other.
- Business addresses only. Sort personal and disposable addresses out with the business email checker before the import.
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CSV Merger FAQ
Short answers to what people ask about merging CSV files.
How do I merge several CSV files into one?
Add them in the merger above. Columns are matched by their header, and you download one CSV with every column of every file.
What if the files have different columns?
Every column is kept. A row from a file without that column gets an empty value there.
How are duplicates found?
By the column you choose, usually the email. Values are compared trimmed and case-insensitive; rows with an empty key are kept.
Which row is kept for a duplicate?
The first by default, or the last if you choose it, for example when the later file is the newer export.
Is my file uploaded?
No. The files are read and merged in your browser and the new file is made there too. Nothing is sent or stored, and nothing from the files reaches analytics.
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