Contact lists
Remove repeated phone numbers before importing into a CRM.
Remove Duplicate Lines
Paste your list and get it back without repeats. Nothing leaves your browser.
Your files stay with you. Your files never leave your browser. This tool runs on your device: nothing is uploaded to our servers, so there is nothing for us to store or see.
How to use it
- Paste your list, one item per line.
- Choose whether to ignore case, spaces and empty lines.
- Copy the cleaned list or download it.
Where it helps
Email lists
Clean an exported list so nobody gets two messages.
Keywords and tags
Tidy long lists of keywords or product tags.
Good to know
Stays in your browser
Your text is processed on your device and never sent to our servers.
Ignore case and spaces
Catch duplicates that differ only in capitals or spacing.
Order kept
It doesn't sort; use Sort lines for that.
Find repeats
Show only the lines that appeared more than once.
Questions people ask
How do you remove duplicate lines from a list?
Paste your list with one item per line, choose whether to ignore case, spaces and empty lines, then copy or download the cleaned list. The first copy of each line is kept by default, so your order stays. Lists with hundreds of thousands of lines work fine, and nothing leaves your browser.
- First kept Order preserved. Or keep the last.
- 100,000s Lines. Handled quickly.
- Show repeats Only duplicates. Optional.
- 0 Data sent. In your browser.
How do I remove duplicate lines?
Paste your list with one item per line, choose whether to ignore case, extra spaces and empty lines, then copy or download the result. Duplicates are removed instantly, and the first copy of each line is kept in its original position, so the list stays in order.
Which copy of a duplicate is kept?
The first one by default, so your original order stays. You can choose to keep the last one instead, which is useful when later lines are more recent, such as the latest entry for a customer in a list exported from a form or spreadsheet.
Can I find only the duplicated lines?
Yes. Tick Show only the lines that were repeated to get one copy of each repeated line. That's handy for finding which customers registered twice or which products appear in two categories, before deciding what to do about them. Then decide which to keep. Review them before deleting anything.
Does it work for thousands of lines?
Yes. Lines are checked using a lookup table, so lists with hundreds of thousands of lines are fine, even on an average laptop. Very large lists can take a moment on older phones, but most contact and keyword lists finish almost instantly. Copy the result straight away.
Does it sort my list?
No, the order is kept exactly as you pasted it, minus the duplicates. Use the Sort lines tool afterwards if you also want it in alphabetical or numerical order. Keeping order is useful when the list's sequence carries meaning. Sort first if you prefer. Both tools are free to use.
Is my list uploaded?
No. Everything runs in your browser, so phone numbers, emails and customer names stay on your device. That's important for contact lists, which contain personal data you're responsible for protecting. Nothing is stored afterwards, and there's no account, so customer details stay with you. That matters for personal data.
How do I clean a phone number list?
First make numbers consistent, for example all with or without +91, using find and replace. Then remove duplicates here with ignore spaces switched on. Numbers written in different formats won't match until they're made consistent. Then remove duplicates again to catch any newly matching lines.
What does ignore case do?
It treats lines that differ only in capital letters as duplicates, so 'Pune' and 'pune' count as the same. Switch it on for names and emails; leave it off when capitals matter, such as for codes or passwords. Emails usually need it on. It's a simple checkbox in the options.
What does ignore spaces do?
It treats lines that differ only in spacing as duplicates, such as extra spaces at the end of a line, which often come from copying spreadsheet cells. It's usually worth switching on for pasted lists. Leave it on for pasted spreadsheet data. Hidden trailing spaces often cause mismatches.
Can I remove empty lines too?
Yes. Choose to remove empty lines, so blank rows from spreadsheets or documents disappear along with the duplicates. The result is a clean list, one item per line, ready to import or paste elsewhere. Gaps from copied documents disappear in the same step. Everything happens in one quick step.
How do I clean a list before importing to a CRM?
Remove duplicates here, tidy spacing with Remove extra spaces, then import the list as a CSV. Marketiism also matches duplicates by phone or email during import, but cleaning first avoids surprises and keeps your contact count accurate. Clean lists import faster. Accurate counts help you plan broadcasts properly.
Can I download the cleaned list?
Yes. Download it as a text file, or copy it to your clipboard and paste it into a spreadsheet, where each line becomes a row. That keeps it easy to reuse in other tools. The file is plain text, which almost every program can open.
Does it work with Hindi?
Yes. It compares lines of any script, including Hindi. Ignore case has no effect on Devanagari, which has no capitals, but duplicate detection and space handling work the same way. Mixed Hindi and English lists work the same way, line by line. Results keep your original line order too.
Does it work on a phone?
Yes. Paste a list on your phone, clean it and copy the result. For very long lists, a computer is more comfortable, but typical lists work fine on a recent phone. No app is needed, and the list stays on the phone the whole time.
Is it free?
Yes. Removing duplicate lines is free, with no sign-up and no limit. It's part of the free text tools from Marketiism, alongside sort lines, find and replace and remove extra spaces. Nothing is added to your text, there's no daily limit, and you can use it for business and client work.
Want this inside your own account?
Marketiism keeps your invoice numbers, GST reports, UPI payment links and WhatsApp reminders in one place. Leave your details and we'll call to set it up for your business, or start the trial yourself.
More Text tools
Sort Lines
Sort a list A to Z, Z to A, by number or length, reverse it or shuffle it.
Remove Extra Spaces
Clean up double spaces, blank lines, tabs and hidden spaces in pasted text.
Text Diff Checker
Compare two texts line by line and see what was added, removed or changed side by side.
Word Counter
Count words, characters, sentences and paragraphs, with reading time and your most used words.
Character Counter
Check your text against limits for X, Instagram, WhatsApp, Meta ads, Google Ads and SMS.
Case Converter
Convert text to upper, lower, title, sentence, camel, snake or kebab case.