CSV emaillist cleaner.
Paste a lead list CSV to remove duplicate emails, trim stray spaces and fix capitals in names and companies. It all runs in your browser.
How it works
- Paste your CSVWith its header row
- Choose the clean-upDuplicates, spaces, capitals
- Download it cleanSafe to open in Excel
Free, no sign-up. Runs in your browser. Nothing you type is sent anywhere.
The tool
Paste your CSV
With its header row. Nothing leaves your browser.
Clean-up
Spaces are trimmed everywhere, and cells that start like a spreadsheet formula are made safe.
Why clean a list.
What the result means, and how to fix what it finds.
Duplicates cost you twice
The same person twice gets your email twice, which looks careless and earns complaints. Lists bought or merged from several sources almost always have duplicates, often with different capitals (Jane@Acme.com and jane@acme.com). We compare email addresses ignoring capitals, and keep the first row of each.
Capitals and spaces show in your email
'Hi JANE' or 'Hi jane ' in a first line looks automated. We trim spaces everywhere and, if you choose, fix capitals in names, companies, titles and places, keeping common short forms like LLC, CEO and UK in capitals. Check unusual names after cleaning: McDonald and van der Berg have their own rules.
Formulas made safe
A cell starting with =, +, - or @ can run as a formula when the file is opened in Excel or Google Sheets, which is a known way to hide harmful content in a list. We put a harmless apostrophe in front of such cells, so the file opens safely.
Clean first, then verify
Cleaning fixes the shape of the list, not whether the addresses work. After cleaning, verify the addresses so you don't send to dead ones. The order matters: verifying a list full of duplicates means paying to check the same address twice.
A good column layout
Lists import cleanly when each column has one job and a clear name. Use one column per field, with simple names like email, first_name, last_name, company, title, website and city. Keep the first name separate from the last name, because 'Hi Jane Smith' reads like a mass email. Avoid line breaks inside cells, which can split one person over two rows. Save the file as CSV in UTF-8, so names with accents keep their letters. And keep a column for where each lead came from, so you can see later which source replies best and which one bounces most.
In mailzy
Import, verify and send from one place.
Upload a CSV to mailzy's Leads: duplicates are skipped, addresses can be verified, and the list goes straight into a campaign.
Questions before you start.
Ask us on the chat if yours isn't here. A real person answers.
Is my list uploaded anywhere?
No. Everything runs in your browser; the list never leaves your computer.
Which column is used for duplicates?
The first column whose name contains 'email'. With no such column, whole identical rows are removed.
How big a file can it handle?
Tens of thousands of rows work fine in a modern browser.
More free tools.
Email Validator
Check syntax, mail servers, disposable and role addresses, and catch-all likelihood, for up to 100 addresses.
Open the toolEmail Permutator
Generate the likely addresses for a person from their name and company domain, ready to verify.
Open the toolDomain Extractor
Turn a list of emails or URLs into clean domains and company names.
Open the toolEverything for cold email, in one place.
Start free for 14 days. No card needed.