Remove Duplicate Lines deletes repeated lines from any list, keeping only the first occurrence of each item. It's perfect for cleaning email lists, keyword lists, product SKUs, log files, CSV columns and any data pasted from a spreadsheet.
Choose whether 'Apple' and 'apple' count as the same item, trim stray spaces, drop blank lines, and optionally sort the result alphabetically with natural number ordering (so item2 comes before item10).
How to use the Remove Duplicate Lines tool
- Paste your list with one item per line.
- Choose your options: ignore case, trim spaces, remove empty lines and sort.
- Click Remove duplicates.
- Copy the cleaned list. The status line tells you how many lines were removed.
Features
- Keeps the first occurrence in the original order, or sorts A→Z or Z→A.
- Case-insensitive matching option.
- Trims whitespace and removes blank lines.
- Natural sorting for numbers.
- Handles hundreds of thousands of lines instantly in your browser.
Tips for best results
To find duplicates in a spreadsheet column, copy the column, paste it here, clean it, and paste it back. Turn on 'Ignore case' for email addresses, because they are not case-sensitive in practice. To compare two lists, check the result with Text Compare.
Duplicate entries creep into data all the time: merged contact lists, exported spreadsheets, scraped keyword lists or log files. Removing them by hand is slow and error-prone, but here thousands of lines are cleaned in a fraction of a second. The tool tells you exactly how many lines were removed, so you can double-check the result.
Compatibility and limits
The Remove Duplicate Lines tool works in every modern browser on desktop and mobile and handles very long texts, even entire books, without slowing down. It understands Unicode, so it works with English as well as Urdu, Arabic, Hindi, Chinese, emoji and accented letters. Because nothing is sent over the network, results appear instantly as you type or click.
Privacy: your files never leave your device
Everything you type or paste is processed instantly in your browser. Your text is never sent to a server, logged or stored, so it's safe to use with drafts, private notes and confidential documents.
Frequently asked questions
Which duplicate is kept?
The first occurrence is kept and later repeats are removed.
Can it ignore upper and lower case?
Yes. Tick 'Ignore case'.
Will it change the order of my lines?
Not unless you choose a sort option.
Is there a line limit?
No fixed limit. Very large lists depend on your device's memory.
Is my data uploaded?
No. Processing happens in your browser.