Remove Duplicate Lines
Remove duplicate lines from text while keeping the original order.
Input Text
Enter text with one item per line.
About Remove Duplicate Lines
Remove Duplicate Lines finds repeated lines and keeps only the first occurrence while preserving the original order. It is useful for cleaning lists, URLs, IDs, email addresses, logs and other text-based data.
How to use Remove Duplicate Lines
- Paste your text into the input area.
- Choose whether duplicate matching should be case sensitive.
- Choose whether whitespace should be removed from the beginning and end of each line.
- Enable Remove empty lines if blank lines should be removed.
- Click Remove Duplicates to create the cleaned result.
What does Remove Duplicate Lines do?
This tool compares each line of your text and removes repeated lines. The first occurrence of each unique line is kept, so the original order of the data is preserved.
Case-sensitive vs case-insensitive matching
| Mode | Example | Result |
|---|---|---|
| Case sensitive | Apple / apple | Treated as different lines |
| Case insensitive | Apple / apple | Treated as duplicates |
Trim whitespace
When Trim whitespace is enabled, spaces and tabs at the beginning and end of each line are removed before duplicate comparison. This can help identify lines that contain the same text but have different surrounding whitespace.
apple
apple
apple
With Trim whitespace enabled, these lines are normalized before they are compared.
When should you remove duplicate lines?
- Cleaning lists of URLs or domains
- Removing duplicate IDs or values
- Cleaning copied spreadsheet or text data
- Removing repeated email addresses
- Cleaning log files and text-based records
- Preparing lists for further processing or analysis
Original order is preserved
The tool does not alphabetically sort your data. It keeps the first occurrence of each unique line and removes later duplicates. This means the order of the remaining lines stays the same as the original input.
Is my text uploaded to a server?
No. Duplicate removal is performed directly in your browser using JavaScript. Your input text is not sent to a server by this tool.
Input limit
The input and result fields support up to 100,000 characters. Larger text may require additional processing resources depending on your browser and device.