Remove Duplicate Lines — Online Sort & Clean Text Tool
Remove duplicate lines from text online. Sort alphabetically A-Z/Z-A, by length, or shuffle. Trim whitespace and clean empty lines. Free, browser-based.
Features
- ✓Remove duplicate lines — exact match or case-insensitive
- ✓Sort lines alphabetically A–Z (ascending) and Z–A (descending)
- ✓Sort by line length — shortest first or longest first
- ✓Reverse line order to flip the entire list
- ✓Shuffle lines randomly for randomization tasks
- ✓Remove empty lines and trim whitespace from each line
- ✓Live line count before and after processing
- ✓One-click copy results to clipboard
- ✓Sample text to quickly test all options
- ✓100% browser-based — your text never leaves your device
How to Use
- 1Paste or type your text (one item per line) into the input area.
- 2Toggle 'Remove Duplicates' to deduplicate lines. Choose case-sensitive or case-insensitive.
- 3Choose a sort order: A–Z, Z–A, by Length, Reverse, or Shuffle.
- 4Toggle 'Remove Empty Lines' and 'Trim Whitespace' for cleaner output.
- 5Click 'Copy' to copy the processed result to your clipboard.
- 6Check the live line count to see how many lines were removed during deduplication.
- 7Use 'Sort by Length' to organize items from shortest to longest for easier scanning.
- 8Use 'Shuffle' to randomize the order for drawing winners or random selection tasks.
Frequently Asked Questions
How do I remove duplicate lines from text?
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Paste your text into the input area, then toggle the 'Remove Duplicates' checkbox. Choose case-sensitive to treat 'Apple' and 'apple' as different, or case-insensitive to treat them as the same. The deduplicated result appears instantly in the output.
What's the difference between case-sensitive and case-insensitive deduplication?
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Case-sensitive dedup treats 'Apple' and 'apple' as different lines (both kept). Case-insensitive dedup treats them as duplicates (only the first occurrence is kept). Use case-sensitive when case matters, case-insensitive for general list cleanup.
How does sorting by line length work?
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Lines are compared by their character count (including spaces). 'Shortest first' sorts from the fewest characters to the most. 'Longest first' reverses that order. Lines with the same length retain their original relative order.
Can I remove blank lines from my text?
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Yes. Toggle 'Remove Empty Lines' to strip out blank lines. You can also toggle 'Trim Whitespace' to remove leading and trailing spaces from each line. Both options can be used together with deduplication and sorting.
Does the shuffle option produce truly random results?
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The shuffle uses the Fisher-Yates algorithm for unbiased randomization. Each permutation of lines is equally likely. Perfect for random selection, drawing winners, or mixing up list order.
Is my text sent to a server?
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No. All sorting, deduplication, and text processing happens entirely in your browser using JavaScript. Your text is never uploaded, stored, or transmitted anywhere.
How do I remove duplicate lines from a CSV or list?
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Paste your list (one item per line), toggle 'Remove Duplicates', and choose case-insensitive for most data cleanup tasks. For CSV files, note that this tool treats each line as a single string — if you need to deduplicate based on a specific column, extract that column first, deduplicate, then rejoin with the original dataset.
What is the difference between 'Sort A-Z' and 'Sort by Length'?
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Sort A-Z arranges items alphabetically (e.g., 'apple', 'banana', 'cherry'). Sort by Length arranges by character count from shortest to longest (e.g., 'fig' (3), 'apple' (5), 'banana' (6), 'cherry' (6)). Use alphabetical for finding items by name; use length for identifying short or long entries.
Can I process very long lists with thousands of lines?
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Yes. The tool processes text entirely in your browser using efficient JavaScript arrays. Lists with 100,000+ lines can be processed, though very large datasets may cause slight delays. The live line count before/after processing helps you verify the results.
What's the best way to clean up a messy list?
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For the cleanest results, use all options together: first trim whitespace to remove leading/trailing spaces, then remove empty lines to eliminate blank entries, enable case-insensitive deduplication to merge 'Apple' and 'apple', and finally sort A-Z for an organized output.
How does the Reverse option work compared to other sorts?
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Reverse simply flips the order of your lines without any sorting comparison. If your list was [A, B, C], reversing gives [C, B, A]. This is different from Z-A sort, which sorts alphabetically in descending order. Use Reverse when you want to preserve groupings but invert the sequence.
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