Line Deduplicator
Remove duplicate lines from your text. Keep the original order or sort the lines. Ideal for cleaning up lists.
Options
Everything about line deduplication
Why remove duplicates from your list?
Duplicate lists cause problems everywhere: a CSV with duplicate emails skews your send stats, a keyword list with duplicates dilutes your SEO strategy, a config file with repeated entries can trigger conflicts.
Manual deduplication is impractical beyond a few dozen lines. On a 5,000-line file, spotting and removing duplicates by eye would take hours and inevitably miss some.
Your text stays on your device. No data is sent to any server — you can safely process email lists, client data, or any sensitive content.
Use cases
- Email marketing managers
- Deduplicate a mailing list before importing it into your sending tool to avoid multiple sends and improve open-rate statistics.
- Developers
- Clean log files, dependency lists, or database exports by stripping duplicate entries.
- SEO specialists
- Merge keyword lists from multiple sources and eliminate duplicates to produce a single, usable list.
- Data analysts
- Prepare text datasets by removing redundant lines before processing or importing into a spreadsheet.
How does deduplication work?
Paste your lines into the input area (one entry per line). Configure options: sort order (original, alphabetical, or reverse), ignore case, trim leading and trailing whitespace.
Click 'Deduplicate'. The tool scans each line, keeps the first occurrence, and discards the rest. Stats are displayed: total lines, unique lines, duplicates removed.
The result appears in a separate area, ready to copy. Original order is kept by default, but you can also sort the output alphabetically.
Frequently Asked Questions
- Is the original line order preserved?
- By default, yes: the tool keeps the first occurrence of each line in its original order. You can then choose to sort alphabetically (A→Z) or in reverse (Z→A).
- Is comparison case-sensitive?
- By default, yes: 'Apple' and 'apple' are treated as two distinct lines. Enable the 'Ignore case' option to treat them as duplicates.
- What does the 'Trim whitespace' option do?
- It strips leading and trailing spaces from each line before comparing. So 'Apple' and ' Apple ' will be treated as identical. Whitespace is also removed from the final output.
- Is my data sent to a server?
- No. All processing runs in your browser via JavaScript. No data is transmitted, stored, or logged.