Merged mailing lists, concatenated log files, combined keyword exports — the result is always the same: duplicates. Removing them by hand is hopeless past a few dozen lines, and spreadsheet dedupe functions require importing, configuring, and re-exporting.
This tool deletes duplicate lines from any text in one click, with options to ignore case and trim whitespace when comparing. It preserves the first occurrence and the original order — paste, clean, copy.
How to Use This Tool
- Paste your list (emails, URLs, keywords, log lines).
- Toggle case-insensitive matching if 'Alice@mail.com' and 'alice@mail.com' should count as one.
- Click to remove duplicates — the count of removed lines is shown.
- Copy the deduplicated list.
Frequently Asked Questions
Does it keep the original order?
Yes — the first occurrence of each line stays in place and later repeats are removed. If you need alphabetical output instead, run the result through the line sorter tool afterwards.
Are 'Apple' and 'apple ' treated as duplicates?
Only if you enable the relevant options: case-insensitive matching equates Apple/apple, and whitespace trimming ignores leading and trailing spaces. With both off, comparison is strict and byte-exact.
How large a list can it handle?
Tens of thousands of lines are processed instantly — deduplication uses a hash set, which scales linearly. Everything runs in your browser, so even huge private lists (customer emails, for instance) never leave your machine.