Duplicate Line Remover & Text Sorter
Paste a list of lines, remove duplicates and blank lines, trim whitespace, and sort — all instantly in your browser.
How to Remove Duplicate Lines
- Paste your list of lines into the input box (a sample with duplicates is pre-filled).
- Choose which options to apply: remove duplicates, case-insensitive matching, remove blank lines, and/or trim whitespace.
- Pick a sort order if you want the result alphabetized, or leave it as "No sorting" to preserve original order.
- Click "Process" to see the cleaned-up result and a stats line showing how many lines were removed.
- Click "Copy Result" to copy the output to your clipboard.
Frequently Asked Questions
Does this work on very large lists?
Yes — processing runs entirely in your browser tab using plain JavaScript string operations, so it can comfortably handle lists of thousands of lines. Extremely large pastes (hundreds of thousands of lines) are limited only by your browser's available memory, not by any artificial cap in the tool.
Can I keep the last occurrence instead of the first?
No — this tool always keeps the first occurrence of each unique line and discards later repeats. There's no option to keep the last occurrence instead; if you need that behavior, you could reverse your input before pasting it in, run the tool, then reverse the output back.
What does case-insensitive duplicate matching actually do?
When enabled, two lines that differ only in letter case — like "Apple" and "apple" — are treated as the same line for duplicate detection, and only the first one encountered is kept in its original casing. When disabled, comparison is exact, so "Apple" and "apple" are both kept as distinct lines.
In what order are the options applied?
The tool trims whitespace from each line first (if enabled), then removes blank lines (if enabled), then removes duplicates (if enabled), and finally applies sorting (if selected). This order means trimming can turn a line that looked non-empty into an empty one before the blank-line filter runs, and sorting always happens last.
Is my text uploaded anywhere while I use this tool?
No — everything happens locally in your browser tab with plain JavaScript. Nothing you paste is sent to a server.