Remove duplicate lines from any text — exact match, trimmed, or case-insensitive.
How to Remove Duplicate Lines Online
Paste your list of items into the input box — one item per line — choose your matching mode, and click "Remove Duplicates." The tool instantly de-duplicates your list and shows how many duplicates were removed.
Three Matching Modes Explained
- Exact match: Removes lines that are identical character-for-character, including spacing
- Trim whitespace: Treats lines as duplicates even if they have extra leading or trailing spaces
- Case-insensitive: Treats "Apple" and "apple" as duplicates (also trims whitespace)
Common Use Cases
Data analysts use this tool to clean up exported CSV columns. Developers use it to deduplicate arrays. SEO professionals use it to clean keyword lists. Writers use it to identify repeated phrases. Email marketers use it to deduplicate mailing lists before import.
Frequently Asked Questions
Does the order of lines change?
No. The tool preserves the original order of lines. The first occurrence of each unique line is kept, and subsequent duplicates are removed.
Can I remove duplicate words (not lines)?
This tool operates on lines. To remove duplicate words, put each word on its own line, then use the tool.
Is there a line limit?
No hard limit. The tool can handle thousands of lines instantly in your browser.
What happens to blank lines?
Blank lines are treated as lines with content (empty content). Multiple consecutive blank lines will be reduced to one.
Can I sort the output after deduplication?
Not in this tool. After removing duplicates, copy the result and use a text editor's sort function.