Remove Duplicate Lines — Free Online Tool
Paste your list and remove duplicate lines in one click. Instantly. No sign-up required.
How to remove duplicate lines
- 1Paste your text with one item per line into the input area
- 2Configure options: case sensitivity, whitespace trimming, and sorting
- 3Click 'Remove Duplicates' to process the text
- 4Review the stats and copy the deduplicated result
About This Tool
When you need to remove duplicate lines from a list, doing it manually is tedious and error-prone, especially with hundreds or thousands of entries. This tool processes your text line by line, keeps only the first occurrence of each unique line, and returns a clean, deduplicated list in seconds.
Common use cases include cleaning up email lists, removing repeated entries from CSV data, deduplicating log files, and tidying up keyword lists for SEO research. The tool provides three configurable options: case-sensitive comparison (so "Apple" and "apple" are treated as distinct or identical, your choice), whitespace trimming to ignore leading and trailing spaces, and optional alphabetical sorting of the output.
After processing, you see clear statistics: the original line count, how many duplicates were removed, and the final unique line count. All processing to remove duplicate lines runs entirely in your browser. Your data is never sent to a server, making this tool safe for proprietary lists, customer data, and sensitive information. There are no usage limits and no sign-up required.
Frequently Asked Questions
When case-sensitive mode is on (default), 'Apple' and 'apple' are treated as different lines. When it is off, they are considered duplicates and only the first occurrence is kept.
When enabled, leading and trailing spaces and tabs are removed from each line before comparison. This prevents lines like ' hello' and 'hello' from being treated as different.
When the sort option is off (default), the unique lines appear in the same order as they first appeared in the input. When sorting is enabled, the output is arranged alphabetically.
Yes. The tool processes text locally in your browser and can handle lists with thousands of lines efficiently. Performance depends on your device's available memory.
Blank lines are treated like any other line. If there are multiple blank lines, only the first one is kept. If you want to remove blank lines entirely, you can use the Find & Replace tool to replace empty lines.