Duplicate email row merger: combine rows that share an address instead of dropping them
In short: A normal dedupe keeps the first row and throws the rest away. This one merges the rows for each address into one, filling blanks from the others, and shows every address it merged. Limit: It matches on the address as written, so Gmail dot and plus versions of one mailbox stay as separate rows.
Upload a CSV or paste it with a header row. Rows with the same email address, ignoring capitals, become one row: the first row is the base, and any blank cell is filled from a later row. If two rows hold different values you choose which wins. You see every address that was merged and can download the result.
Price: this tool is free. Checking a whole email list is from $9/mo, and the first 100 checks are free with Google, no card. Check your list free nowSee pricing
Blank cells are always filled from another row.
Sample result
Five example rows become 3: two addresses were on two rows each, and 2 blank cells were filled.
- Rows out
- 3
- Rows in
- 5
- Cells filled
- 2
What this means for you
Nothing from the second row is lost; each address is then checked once.
- Blanks filled from other rows
- You pick which value wins
- Every merge listed
- Rows with no address kept
- Duplicates
- Merge
- CSV
By SimpleVerifier Team · Last updated · Runs in your browser; nothing you paste is sent to us
Rows merged, now check each address once.
- Download the merged list, or use the check button under the result, which carries the merged addresses across.
- Upload or paste it at /verify. Every address gets a live mailbox check, and the first 100 email checks are free with a Google sign-in, no card.
How do I merge duplicate rows in a CSV?
- Upload the file as a CSV or .xlsx, or paste the cells with the header row first. It needs an Email column.
- Choose what happens when two rows hold different values: keep the first, keep the last or keep the longer one.
- Press Merge the duplicates and read the table of addresses that were on more than one row.
- Download the merged list, with one row per address and the blanks filled in.
Example
- You enter
- Five rows: ava@example.com twice (the second as AVA@example.com with a phone number the first lacks), ben@example.org twice (the second adds a company) and cara@example.net once.
- You get
- 5 rows in, 3 rows out. 2 addresses were on more than one row; 2 blank cells were filled and none disagreed.
- Limits
- Runs in your browser; nothing is uploaded. Where two rows disagree one value wins by your rule; it cannot tell which is right.
What does merging do that deduplicating does not?
A plain remove duplicate emails keeps the first row for each address and discards the others. If the first row has no phone number and the second does, the number is lost. Merging keeps one row per address and carries the phone number across.
Rows with the same address often come from joining exports from different tools, each with a different set of filled columns. Merging them is the step before an import, as in merge lead lists without duplicates.
What happens when two rows disagree?
If both rows have a value in a column and the values differ, only one can stay. You choose: the value from the first row, from the last row, or the longer of the two, which is often the fuller name or address. Differences in capital letters alone are not counted as a disagreement. The table shows how many cells disagreed for each address, so you know which merges to look at.
Which rows are left alone?
A row with no email address in the Email column cannot be matched, so it is kept as it is and placed after the merged rows. To compare two files by address and see which fields changed, use compare two CSV files. To find people who appear twice under different addresses, use the duplicate contact finder.
Who uses this tool, and for what?
- Sales ops
- Join an Apollo export and a CRM export and keep every field each one knew about a contact.
- Marketers
- Combine signup forms that were exported separately, so each subscriber has one full row.
- Cold emailers
- Merge lead files from two sources before a send, so a person gets one email and the best data.
What can’t this tool tell you?
- It matches on the address as written, so Gmail dot and plus versions of one mailbox stay as separate rows.
- When two rows disagree, one value wins by your rule; it cannot tell which is correct.
- It never joins two values in one cell, so it will not combine two phone numbers.
- It cannot say whether an address exists; that needs a mailbox check.
Common questions
- Are addresses matched ignoring capital letters?
- Yes. Ava@Example.com and ava@example.com are the same row. Spaces around the address are ignored too.
- Which row is the base?
- The first row that holds the address, so the merged rows stay in the order the addresses first appear.
- Does it combine values from two cells?
- No. It never joins two values into one cell. When two rows differ, one value wins by your rule, and the table counts the disagreement.
- What about Gmail dots and plus tags?
- It matches the address as written. Use the remove duplicate emails tool when you want Gmail dot and plus versions treated as one.
- Is anything deleted without being counted?
- No. Rows in, rows out, merged addresses and filled cells are all shown, and rows with no address are kept.
- Is my file uploaded?
- No. The file is read in your browser and goes nowhere.
A tidy list can still be full of dead addresses.
Extracting, deduplicating and syntax checks all work on the text of an address. None of them can tell whether the mailbox exists. Only the server that hosts it can answer that, through an SMTP check, and that is what the paid product does.
- Upload the cleaned file as it is: CSVs up to 100,000 rows
- A real SMTP mailbox check on every row, with catch-all detection
- Small list? Starter at $9/mo covers 2,500 emails a month, cancel anytime
Plans from $9 a month, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.