Add row number to CSV: add a numbered column, or count contacts within each company
In short: Upload a list, name the new column, choose where it starts and how it counts, and download the file with a number on every row. Limit: Numbers are plain text in the CSV; a spreadsheet may drop leading zeros when it opens the file.
Upload a CSV or .xlsx file, or paste it with a header row. Name the new column and choose where it starts, how much it counts up by, and how many digits to pad with zeros. Optionally restart the count for each value of another column, such as Company. Download the file with the number added first or last.
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
Sample result
Four example rows are numbered within each company: Ava 1, Ben 2, Cara 1 at Globex and Dev 3.
- Rows numbered
- 4
- Last number
- 3
- Columns now
- 4
What this means for you
A row number does not show which addresses exist; a check does.
- Your start and step
- Zero padding
- Restart per company
- First or last column
- Row number
- CSV
- Rank
By SimpleVerifier Team · Last updated · Runs in your browser; nothing you paste is sent to us
Rows numbered? Check the addresses before you import.
- Download the file, or use the check button under the result, which carries its 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 add a row number column to a CSV?
- Upload the file as a CSV or .xlsx, or paste the cells with the header row first.
- Name the new column and choose where it goes, the start, the step and any zero padding.
- To rank contacts inside each company, choose that column under restart the count.
- Check the preview and download the file.
Example
- You enter
- Four rows with Name, Company and Email (Ava, Ben and Dev at Acme, Cara at Globex), a column named Row at the start, counting from 1 and restarting for each company.
- You get
- Ava is 1, Ben is 2, Cara is 1 (first at Globex) and Dev is 3. 2 counts were started and Row is added as the first column.
- Limits
- Runs in your browser; nothing is uploaded. Companies are matched by exact text apart from capitals, so Acme and Acme Inc count separately.
When do you need a row number?
A row number gives every lead a stable ID to quote when you split a list across people, match rows after sorting, or ask a vendor about row 4,812. It also lets you put a file back in its original order after a sort.
Padding with zeros, such as 0001, keeps numbers in the right order when a tool sorts them as text.
How does numbering within a group work?
Pick a column such as Company or Domain and the count restarts at your start value each time a new value appears: the first contact at Acme is 1, the second is 2, the first at Globex is 1 again. Values are matched without regard to capitals or spaces at the ends.
Rows do not need to be sorted by that column. The count follows the order of the rows in the file, so a contact at Acme further down is still counted after the earlier ones. To drop everyone past the second contact, use the limit contacts per company tool.
What if my header already has that name?
The tool never overwrites a column. If Row is taken, the new column is called Row (2). To add or reorder columns by hand, use the CSV column editor; to fill empty cells, use fill down blank cells.
Who uses this tool, and for what?
- Cold emailers
- Number contacts within each company to send the first contact now and the rest later.
- Agencies
- Add stable IDs to a lead list before splitting it across several people.
- Data teams
- Keep a way back to the original row order before sorting or de-duplicating a file.
What can’t this tool tell you?
- Numbers are plain text in the CSV; a spreadsheet may drop leading zeros when it opens the file.
- Group values are matched exactly apart from capitals and end spaces, so Acme and Acme Inc count separately.
- It does not sort the rows.
- Only the first sheet of a workbook is read.
Common questions
- Can the numbering start at 0?
- Yes. Start at 0 or any whole number above it, and count up by 1 or more.
- How do I get 001, 002, 003?
- Set the digits to 3. Numbers shorter than that are padded with leading zeros.
- Can it number contacts per company?
- Yes. Choose the company or domain column under restart the count, and each value starts again at your start number.
- Does it sort my file?
- No. Rows stay in their original order and the numbers follow that order.
- Where does the new column go?
- First or last, as you choose. Nothing else moves.
- Is my file uploaded?
- No. It 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.