Remove Duplicate Lines

Remove duplicate lines from any list

This tool removes repeated lines from a list and keeps only the first copy of each. The result keeps your original order unless you choose to sort it, and a summary shows how many lines went in, how many duplicates were removed and how many remain.

Duplicates creep into email lists, keyword research, URL lists, log files and any column copied out of a spreadsheet. Cleaning them by hand is slow and error-prone, and a plain text tool is often the quickest fix.

How to use it

1. Paste your list into the left box, one item per line.
2. Choose your options: case sensitivity, trimming spaces, removing empty lines and sorting.
3. Read the summary to see how many duplicates were removed.
4. Click Copy to take the unique lines with you.

Common uses

• Marketers clean keyword and email lists before importing them.
• Developers dedupe logs, URLs, IDs and configuration lines.
• SEO specialists merge keyword exports from several tools.
• Researchers tidy reference and participant lists.
• Spreadsheet users dedupe a single column quickly.

Tips

• Keep "Trim spaces" on, because a trailing space makes two identical lines look different.
• Turn on case sensitive only when "Apple" and "apple" really are different items.
• Lines that differ even slightly, such as extra punctuation, are treated as different lines.

Frequently asked questions

Does it keep the original order?

Yes. The first occurrence of each line stays where it was. Tick "Sort A–Z" if you would rather have the unique lines in alphabetical order.

Is the comparison case sensitive?

Not by default, so "Apple" and "apple" count as the same line and the first one is kept. Tick "Case sensitive" to treat them as different.

How many lines can it handle?

Lists of tens of thousands of lines are normally processed instantly. The practical limit is your browser and device memory.

What happens to empty lines?

They are removed by default. Untick "Remove empty lines" to keep them in place; blank lines are never counted as duplicates.

Privacy

Everything runs locally in your browser. Your text is never uploaded, stored or shared, and you can use the tool offline once the page has loaded.

Related tools: Alphabetize List · Compare Text · Character Counter · Slug Generator