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 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.