How to use the Remove Duplicate Lines tool
- Paste your listPut one item per line: emails, keywords, URLs, product codes or any text.
- Set the optionsChoose whether “Apple” and “apple” count as the same, whether extra spaces are ignored and whether empty lines are removed.
- Sort if you likeKeep the original order, or sort A–Z, Z–A, numerically or by length.
- Copy the resultCopy the cleaned list or download it as a text file. The counters show how many duplicates were removed.
Features
- Keeps the first occurrenceThe original order is preserved and the first copy of each line is kept.
- Smart matchingOptionally treat lines that differ only in letter case or spacing as duplicates.
- Find the duplicatesSwitch the view to see only the repeated lines, with how many times each appears.
- Unique-only modeKeep only the lines that appear exactly once in your list.
- Fast and privateLarge lists are processed instantly in your browser and never uploaded.
Why remove duplicate lines?
Duplicates creep into lists all the time: email addresses merged from several sign-up forms, keywords exported from different SEO tools, URLs collected from crawls, or product SKUs copied from multiple spreadsheets. Removing them by hand is slow and error-prone. This tool cleans a list of any length in a fraction of a second.
Common uses
- Email and contact lists: avoid sending the same newsletter twice to one person.
- SEO keyword research: merge keyword exports and remove overlaps before grouping.
- Developers and data work: deduplicate IDs, log entries or values before importing.
- Writing and research: clean up lists of references, tags or names.
Understanding the options
| Option | Effect | Example |
|---|---|---|
| Ignore upper/lower case | Lines that differ only in capitalization are duplicates | “Apple” = “apple” |
| Ignore extra spaces | Leading, trailing and repeated spaces are ignored | “ new york ” = “new york” |
| Remove empty lines | Blank lines are dropped from the result | |
| Keep only lines that appear once | Every line that has any duplicate is removed entirely | Find values unique to one list |
When duplicates are found, the version that appears first in your list is kept. With “Ignore extra spaces” on, that version is also tidied up.
Tip: compare two lists
To find items that appear in only one of two lists, paste both lists one after the other and turn on Keep only lines that appear once. Items present in both lists disappear, leaving only the differences. To find items common to both lists, use Show the duplicates instead.
Working with spreadsheets
To clean a column from Excel or Google Sheets, copy the column, paste it here, then paste the result back. Each cell becomes one line. For data with several columns, deduplicate on the column that identifies each row, such as an email address or ID.