Usage and specifications
This guide is currently available in English.
How to use this tool
Paste one item per line. Duplicate checking and the deduplicated result update automatically. Choose how empty lines are handled, then copy the output.
Understanding the result
The first occurrence is kept in its original order. The duplicate count includes every line in a repeated group: A, A, B has two duplicate-group lines, although only one line is removed.
When to use it
Clean product codes, participant lists or configuration values where each line is one item. To extract the part before @ in an email address, use the Email Address Splitter instead.
Practical tips
Keep a copy of your original input. Spaces and letter case are significant, so two visually similar lines can remain separate.
Worked examples
Keep the first occurrence
| Input / settings | Result |
|---|---|
apple banana apple | apple banana |
Specifications and limitations
- Comparison is exact and case-sensitive. Apple, apple and a line with a trailing space are different.
- This is a line-based tool, not a CSV column-aware deduplicator.
- Text input is limited to 5,000,000 JavaScript string units.