CSV list cleaner

Drop a lead list and Ken cleans names, companies, titles and domains, removes duplicates and flags freemail, role and disposable emails, in your browser.

CSV or Excel, up to 200,000 rows. Exports from Apollo, Sales Navigator, HubSpot or any CRM.
Runs in your browser. The file never leaves your device.CSV or Excel, up to 200,000 rows
Ken runs these cleaners on every list you import.
Import the file and Ken cleans it again, verifies the addresses and builds the campaign from it.
Start free - 1,000 credits, no card

What the list cleaner does

Drop a CSV or Excel export from Apollo, Sales Navigator, Clay, HubSpot or any CRM and every cleaner runs in one pass. The file is parsed inside your browser tab by a background worker, so nothing is uploaded and closing the tab deletes it.

It maps your columns automatically, then cleans names, company names, job titles and domains, removes duplicates and flags the rows that would hurt a campaign.

How to read the result

The stat chips at the top count what happened: duplicates removed, freemail addresses flagged, role and disposable addresses removed, empty or malformed emails dropped. Below them is a before and after table of the rows that changed.

  • A removed row goes to a second file, with the reason, so nothing is lost.
  • A flagged row stays in the list. You decide whether it goes.
  • A fixed cell keeps its column. Only the value changes.

How to use it before a campaign

Run it on every export before it reaches a sending tool. Check the column mapping first, because a wrong guess there spreads through every cleaner. Then look at the removed file for anything you want back, choose whether freemail addresses stay, and download CSV or Excel.

Clean is not the same as deliverable. Verify the addresses next, and run the merge tag checker if your template uses fields the list might leave empty.

Why it matters for cold email

Bad rows cost more than the send. Role addresses like info@ and disposable domains bounce or never reach a person, and bounces count against the sending domain. "Hi JOHN," and "ACME LOGISTICS LLC" in the first line tell the reader the email came from a mail merge. Removing them before the first send is cheaper than repairing a domain's reputation afterwards.

Questions

Does my file get uploaded anywhere?
No. The parser and every cleaner run in your browser tab, and the download is built there too. If you choose to email yourself the summary, it carries counts, the file name and the column mapping, never rows.
Why are freemail addresses kept by default?
Because many of them are real buyers. Founders, consultants and small agency owners often run their business on Gmail or Outlook. The cleaner flags them so you can see how many there are, and one switch removes them if the campaign should only go to work addresses.
What counts as a duplicate?
Two rows with the same email after trimming and lowercasing, with Gmail dots and +tags ignored because Gmail delivers [email protected] to [email protected]. Two rows with the same LinkedIn profile also match. The first row stays and the rest go to the removed file. The before and after table says which row each one repeats.
How large a file can it take?
Up to about 200,000 rows in a current desktop browser. The work runs in a background worker, so the page stays responsive while it parses. For a bigger file, run it through the split CSV tool first and clean the parts.
Which exports does the column mapping recognise?
Apollo, Sales Navigator, HubSpot, Instantly and Smartlead headers map on their own, and most other CRM exports match by column name. You can correct any column by hand before the cleaners run. Columns the cleaner does not recognise are copied through unchanged.

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