Remove Duplicate Lines
A powerful tool to remove duplicate lines from your text while preserving the original order. Perfect for cleaning up lists, logs, data files, and any text containing repeated lines.
Matching Options
Format Preservation
Features
- Remove duplicate lines
- Case-sensitive matching
- Whitespace handling
- Keep first/last occurrence
- Preserve formatting
- Unicode support
- Undo/redo support
Instructions
- Paste or type text in the editor
- Choose duplicate handling options
- Click "Remove Duplicates"
- Copy the processed result
Interesting History
The concept of removing duplicates dates back to early computing in the 1960s when storage was expensive. The Unix command 'uniq' was created in 1971 by Douglas McIlroy at Bell Labs, becoming one of the most used text processing tools. This simple yet powerful concept has evolved from command-line tools to modern web applications, making text processing accessible to everyone.
Frequently Asked Questions
How does the duplicate line removal process work?
The tool processes text line by line, maintaining a record of unique lines while preserving the original order. It handles various edge cases including empty lines, whitespace variations, and special characters.
Does it preserve the original line order?
Yes, the tool maintains the original order of lines, keeping the first occurrence of each unique line while removing subsequent duplicates.
How are empty lines handled?
Empty lines are treated as unique lines by default. The tool can be configured to either preserve or remove empty lines based on your needs.
Is the comparison case-sensitive?
Yes, the comparison is case-sensitive by default. This means "Line" and "line" are treated as different lines.
How does it handle whitespace?
The tool intelligently handles whitespace, trimming leading and trailing spaces while preserving internal spacing.
Can it process large texts?
Yes, the tool is optimized for performance and can handle large texts efficiently using modern algorithms.
Does it support Unicode characters?
Yes, full Unicode support is included, making it suitable for processing text in any language or with special characters.
How are different line endings handled?
The tool automatically normalizes different line endings (CRLF, LF) to ensure consistent processing across different platforms.
Is the processed text secure?
Yes, all processing is done locally in your browser. No data is sent to any server or stored anywhere.
Can I undo the deduplication?
Yes, the tool includes undo/redo functionality to help you experiment with different deduplication options.