Remove Duplicate Lines

How to use Remove Duplicate Lines

1. Paste your list with one item per line.
2. Choose whether to ignore case, trim spaces and remove blank lines.
3. Copy the unique lines from the result.

Why duplicates creep in

Lists grow by copy-and-paste. Email exports, keyword research, scraped URLs and server logs routinely contain repeats. Removing them keeps mailing lists clean (so nobody gets two emails), makes keyword lists accurate and shrinks files.

Tips for accurate results

• Turn on “Trim spaces” so “apple” and “apple ” (with a trailing space) match.
• Turn on “Ignore case” for emails and tags where capitalisation does not matter.
• Keep case sensitivity on for case-sensitive data such as file paths or passwords.
• Sort the result afterwards with the Sort Lines tool if you also want it alphabetical.

Limits

The tool compares entire lines, so “apple pie” and “apple pie recipe” are different. For very large files with hundreds of thousands of lines, results still appear quickly because the check uses a hash set, but your browser tab may need a moment to render the output.

Dedupe in real workflows

A common pattern is to export a column from a spreadsheet, remove duplicates here and paste the unique values back, which is much faster than a pivot table for a simple list. Another is cleaning a keyword research list that merged several sources, where the same phrase appears with different spacing or capitalisation. Turning on Trim spaces and Ignore case together catches most of those.

Remember that the tool keeps the first occurrence, so if the order carries meaning, such as a ranked list, the highest-ranked copy is the one that survives.

Why use this remove duplicate lines tool

• Keeps original order. The first occurrence of each line is kept.
• Case-insensitive option. Treat “Apple” and “apple” as the same.
• Counts removed lines. See how many duplicates were dropped.

Frequently asked questions

More free tools