🗑️ Remove Duplicates

Delete repeated lines and keep only unique values instantly

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How to Remove Duplicate Lines Online

Removing duplicates from your data is simple with our free tool. Here's how it works:

The tool keeps the first occurrence of each item and removes all subsequent duplicates. Your original order is preserved (unless you choose "Sort + Dedup").

Deduplication Options Explained

🔤 Remove Duplicates (Exact Match)

The default mode performs an exact, case-sensitive comparison. "Apple" and "apple" are treated as different items. Use this when capitalization matters in your data.

🔠 Ignore Case

Treats "APPLE", "Apple", and "apple" as the same item. Perfect for cleaning email lists, names, or any data where capitalization is inconsistent. The first occurrence's capitalization is preserved.

📊 Sort + Dedup

Combines alphabetical sorting with duplicate removal in one click. Great for creating organized, clean lists for imports or reports. Saves time when you need both operations.

🔍 Show Dupes

Instead of removing duplicates, this shows you only the items that appear more than once. Useful for auditing data quality or finding problematic entries before deciding what to do with them.

Common Use Cases

📧 Cleaning Email Lists

Imported a contact list with duplicate addresses? Paste it here to get a clean, unique list ready for your email marketing platform. Prevents sending multiple emails to the same person.

📊 Spreadsheet Data Cleanup

Copy a column from Excel or Google Sheets, paste it here to remove duplicates, then paste it back. Faster than using Excel's built-in duplicate removal for quick tasks.

🛒 Product SKU Deduplication

Working with inventory data? Remove duplicate product codes, SKUs, or barcodes to ensure accurate stock counts and prevent ordering errors.

👥 Name List Cleanup

Consolidating attendee lists, member rosters, or contact databases? Use "Ignore Case" to catch duplicates like "John Smith" and "john smith".

💻 Log File Analysis

Extract unique error messages, IP addresses, or user IDs from log files. Combined with our IP Extractor or Email Extractor for powerful data analysis.

🔗 URL Deduplication

Cleaning up a list of links for SEO analysis or web scraping? Remove duplicate URLs before processing to save time and avoid redundant requests.

Frequently Asked Questions

How do I remove duplicate lines from text?
Paste your text into the editor and click "Remove Duplicates". The tool keeps the first occurrence of each line and removes all repeats. You'll see exactly what was removed in the right panel.
Can I ignore capitalization when removing duplicates?
Yes! Click "Ignore Case" to treat "Apple" and "apple" as the same item. This is useful when your data has inconsistent capitalization. The first occurrence's original capitalization is preserved.
How do I find which items are duplicated without removing them?
Click "Show Dupes" to see only the items that appear more than once in your list. This helps you identify problematic entries without removing them yet—useful for data auditing.
Is my data safe when using this tool?
Absolutely. All processing happens locally in your browser using JavaScript. Your data never leaves your device and is never sent to any server. It's 100% private.
Can I undo after removing duplicates?
Yes! Click the "Undo" button to restore your original text. The tool keeps a history of changes so you can always go back if needed.
What's the maximum amount of data I can process?
Since processing happens in your browser, the limit depends on your device's memory. Most modern devices can handle hundreds of thousands of lines without issues. For very large datasets (1M+ lines), consider using a desktop application.

Related Text Tools

Need to do more with your data? Try these complementary tools:

Sort Text A-Z Compare Lists Extract Emails Clean Text Case Converter Word Counter

🔒 100% Private & Secure

Your data privacy is our priority. All duplicate removal happens locally in your browser—your text is never uploaded to any server. We can't see, store, or access your data. Use this tool with complete confidence for sensitive information like email lists, customer data, or confidential documents.