Remove Duplicate Lines
Remove repeated lines from any text while preserving first-seen order. Useful for logs, exports, keyword lists, and pasted data.
DeduplicateListsClient-sideFree to use
Updates instantly
How to use
- Paste your lines. One item per line works best.
- Choose case sensitivity. Treat A and a as the same line or different lines.
- Copy the deduplicated output. First-seen order is preserved.
Common use cases
- Cleaning keyword or outreach lists
- Deduplicating noisy log output
- Preparing unique CSV-like line exports
Frequently asked questions
- What is this tool best used for?
- It is ideal for cleaning up any line-based list where repetition crept in: keyword research exports, email address lists, URL sets, log files, and CSV row dumps. Paste the list, run the tool, and you get a clean set with each unique line appearing exactly once.
- How does it decide which occurrence to keep?
- The tool preserves the first occurrence of each line and discards any later duplicates. Your original ordering is maintained, so the output reads in the same sequence as the input, just without the repeats.
- Is the comparison case-sensitive?
- By default, yes. "Foo" and "foo" are treated as two distinct lines. If you enable the case-insensitive option, both collapse to a single entry (the first-seen casing is kept in the output).
- Does my text get sent to a server?
- No. The deduplication runs entirely in your browser. Your text never leaves your device, so it is safe to use with sensitive or private data.
- Will "foo " and "foo" be treated as duplicates?
- Not by default. A line with trailing whitespace and the same line without it are treated as different values because the comparison is exact. If your data has inconsistent spacing, trim whitespace before deduplicating, or use the trim option if one is available.
- What happens to blank lines?
- Blank lines count as duplicates of each other, so multiple consecutive blank lines will be collapsed down to one. If you want all blank lines removed entirely, run the output through the Remove Empty Lines tool afterward.
Related tools
How to use
- Paste your lines. One item per line works best.
- Choose case sensitivity. Treat A and a as the same line or different lines.
- Copy the deduplicated output. First-seen order is preserved.
Common use cases
- Cleaning keyword or outreach lists
- Deduplicating noisy log output
- Preparing unique CSV-like line exports
Frequently asked questions
- What is this tool best used for?
- It is ideal for cleaning up any line-based list where repetition crept in: keyword research exports, email address lists, URL sets, log files, and CSV row dumps. Paste the list, run the tool, and you get a clean set with each unique line appearing exactly once.
- How does it decide which occurrence to keep?
- The tool preserves the first occurrence of each line and discards any later duplicates. Your original ordering is maintained, so the output reads in the same sequence as the input, just without the repeats.
- Is the comparison case-sensitive?
- By default, yes. "Foo" and "foo" are treated as two distinct lines. If you enable the case-insensitive option, both collapse to a single entry (the first-seen casing is kept in the output).
- Does my text get sent to a server?
- No. The deduplication runs entirely in your browser. Your text never leaves your device, so it is safe to use with sensitive or private data.
- Will "foo " and "foo" be treated as duplicates?
- Not by default. A line with trailing whitespace and the same line without it are treated as different values because the comparison is exact. If your data has inconsistent spacing, trim whitespace before deduplicating, or use the trim option if one is available.
- What happens to blank lines?
- Blank lines count as duplicates of each other, so multiple consecutive blank lines will be collapsed down to one. If you want all blank lines removed entirely, run the output through the Remove Empty Lines tool afterward.