About this tool
Whether you're cleaning a list of emails, log lines, or CSV rows, duplicate lines are tedious to find by eye. This remove duplicate lines tool strips duplicates while preserving the first occurrence's original order, with optional case-insensitivity, whitespace trimming, and alphabetical sorting.
How to use it
- 1Paste your text, one item per line.
- 2Toggle case-sensitivity, trimming, and sorting as needed.
- 3Copy the deduplicated result.
Common mistakes to avoid
- Leaving case-sensitivity on when "Email" and "email" should be treated as the same duplicate.
- Not trimming whitespace, which can cause visually identical lines to be treated as different due to trailing spaces.
Use cases
- Cleaning a list of email addresses or usernames before an import.
- Deduplicating a list of keywords, tags, or log entries.
Frequently asked questions
Does this preserve the order of the first occurrence?
Yes, unless you enable sorting — by default, the first time each unique line appears is kept in its original position.