Remove Duplicates
Remove duplicate lines from any block of text
About Remove Duplicates
Duplicate lines are a common problem in data lists, email exports, keyword files and CSV data. This free Remove Duplicate Lines tool instantly identifies and removes repeated lines from any block of text. Paste your list, click remove, and get a clean deduplicated result — with optional case-insensitive matching for flexible deduplication. No download, no signup required.
How to Use Remove Duplicates
- 1Paste your text with duplicate lines into the input area.
- 2Choose whether the comparison is case-sensitive or case-insensitive.
- 3Click "Remove Duplicates" to clean the list.
- 4Copy the deduplicated output with the "Copy" button.
Common Use Cases
Toggle case-insensitive mode if "Apple", "apple" and "APPLE" should all count as the same duplicate.
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Frequently Asked Questions
What is the fastest way to remove duplicates from a large list?
Paste your list into this tool and click "Remove Duplicates" — it handles thousands of lines instantly in your browser. For very large datasets (millions of rows), use command-line tools: sort file.txt | uniq > output.txt on Linux/Mac, or use Excel's Remove Duplicates feature for spreadsheet data.
What does case-insensitive deduplication mean?
With case-insensitive deduplication, "apple", "Apple" and "APPLE" are treated as the same value and only one copy is kept. With case-sensitive deduplication (default), these three are considered different values and all three are kept. Use case-insensitive mode for email lists and keyword lists where capitalization does not matter.
How do I remove duplicate lines while preserving the original order?
This tool preserves insertion order — the first occurrence of each line is kept, and subsequent duplicates are removed. The resulting list maintains the same relative order as the original input, which is important for keeping lists organized as they were originally.