Remove Duplicate Lines
Clean up your text by removing duplicate lines instantly. Choose case-sensitive or case-insensitive comparison, keep first or last occurrence, and use additional functions like sort (A-Z, Z-A), reverse, and shuffle. Perfect for cleaning lists, removing duplicate entries from data, or organizing text files.
Options
When unchecked, 'Hello' and 'hello' are treated as duplicates
Enter text above to remove duplicates and manipulate lines
Each line will be treated as a separate item
💡 Tip: Combine multiple operations for powerful text manipulation. All processing happens in your browser with no uploads!
Embed This Tool
Add this tool to your website with customizable styling
How to Use
- 1 Enter your text with one item per line in the text area above. Each line will be treated as a separate item for duplicate detection.
- 2 Choose your options — Enable "Remove duplicate lines" to clean your list. Toggle "Case-sensitive" to control whether 'Hello' and 'hello' are treated as different (case-sensitive) or the same (case-insensitive).
- 3 Select which occurrence to keep — Choose "First occurrence" to keep the first instance of each duplicate, or "Last occurrence" to keep the last instance. This is useful when your list has a chronological order.
- 4 Use additional functions — Click "Sort A-Z" or "Sort Z-A" to alphabetically sort your lines, "Reverse" to flip the order, or "Shuffle" to randomize the list. These work independently or in combination with duplicate removal.
- 5 Review the statistics — See how many lines you started with, how many remain after processing, and how many duplicates were removed.
- 6 Copy your cleaned text — Click the Copy button to copy the processed text to your clipboard, ready to paste anywhere.
💡 Pro Tip: You can combine functions! For example, remove duplicates first, then sort A-Z to get a clean, alphabetically ordered list.
Frequently Asked Questions
What's the difference between case-sensitive and case-insensitive comparison?
Case-sensitive comparison treats uppercase and lowercase letters as different characters. For example, "Apple", "apple", and "APPLE" would be considered three different lines. Case-insensitive comparison ignores letter casing, so those three variations would be treated as duplicates, and only one would be kept. Use case-sensitive when exact matches matter (like code or IDs), and case-insensitive when you want to catch variations in capitalization (like names or words).
When should I keep the first occurrence vs. the last occurrence?
Choose "First occurrence" when the earliest entry is most important or authoritative. This is common when processing logs, maintaining original order, or when the first entry has priority. Choose "Last occurrence" when the most recent entry should be kept, such as when processing updated records, maintaining the latest version, or when newer data supersedes older data.
Can I use multiple functions together?
Yes! The functions work independently and can be combined. For example, you can remove duplicates first, then sort the result alphabetically. Or shuffle your list and then remove duplicates to get a random selection of unique items. Each button applies its function to the current text, so you can chain operations in any order you like.
What happens to empty lines?
Empty lines (blank lines with no characters) are treated as valid lines and will be processed like any other line. If you have multiple empty lines and "Remove duplicates" is enabled, only one empty line will be kept (first or last, depending on your setting). If you want to remove all empty lines, you can use a text editor's find-and-replace feature before pasting your text here.