Duplicate line checker
Paste a list — email addresses, keywords, URLs, names. The line count and unique word count together show you how much repetition you are carrying.
Repeated entries
Numbers appear here once you add text.
- Free, no sign-up
- Counts as you type
- Your text never leaves your browser
Where duplicates come from
Lists accumulate repetition almost automatically. Exports from two systems get concatenated, a keyword research file merges three tools' output, a mailing list is compiled from several sources. The duplicates are rarely visible at a glance because they sit hundreds of lines apart.
Check for these before you deduplicate
- Trailing whitespace. Two lines that look identical but differ by one trailing space are not duplicates to a computer.
- Case differences. Example@site.com and example@site.com are the same mailbox and different strings.
- Near-duplicates. URLs differing only by a tracking parameter, or names with and without a middle initial.
- Legitimate repeats. In a transaction log, the same value twice is data, not error.
Deduplicating an email list before sending is not optional housekeeping. Sending the same message twice to one address damages sender reputation and is a common trigger for spam filtering.
Common questions
Is the comparison case-sensitive?
The word frequency panel is not case-sensitive, so entries differing only by capitalisation are grouped together. Normalise to lowercase first with the case converter if you want an exact match.