Duplicate Line & Word Finder
Paste a list to remove duplicate lines or words, show only the repeats, or count each item, with or without matching case.
Your list
Cleaned list
How to use the duplicate line finder
Paste your list with one item per line, or switch to word mode to compare individual words. Choose the output you want: a list with duplicates removed, only the items that repeat, or a count of each item. Then decide whether case matters. Results update instantly, with totals for all items, unique items and duplicates removed.
Why duplicates matter
Duplicates hurt data quality in almost every marketing workflow. Duplicate emails inflate your list size and can hurt deliverability. Duplicate keywords lead to pages competing with each other. Duplicate URLs muddy sitemaps and canonical tags. Duplicate SKUs corrupt inventory reports. A quick dedupe before you import or upload saves hours of cleanup later.
Common use cases
- Cleaning email lists before importing them into Mailchimp, Klaviyo or HubSpot
- Deduping keyword research exports before writing a content brief
- Removing duplicate URLs from a sitemap or backlink export
- Cleaning SKU lists before an inventory upload
- Finding repeated lines in error logs
- Deduplicating contacts before a CRM import
Case sensitivity matters more than you think
"Email@domain.com" and "email@domain.com" reach the same inbox in practice, because mail providers treat addresses as case-insensitive. Ignore case when deduping emails, domains and user names. Match case only when it carries meaning, such as exact-match keywords or code identifiers.
Frequently asked questions
Does it keep the order of my list?
Yes. In remove duplicates mode, the first occurrence of each item stays in its original position and later copies are removed.
How does it handle extra spaces?
Spaces at the start and end of each line are removed before comparing, so "apple " and "apple" count as duplicates. Empty lines are ignored.
How many lines can I paste?
Everything runs in your browser, so the only limit is your device's memory. Very large lists of several hundred thousand lines are easier to handle in chunks.
Can I dedupe a CSV by one column?
Paste only the column you want to check. For deduping across several columns, use a spreadsheet or a script.