What to select
Paste newline-separated values, review duplicate counts, then keep the first or last occurrence.
Duplicate Line Detector & Remover
Count repeated lines and keep the first or last occurrence with case controls.
We use reasonable safeguards to help protect your files and information while you use the service.
0 / 500,000 characters
- Total lines
- 1
- Unique lines
- 1
- Duplicate lines
- 0
- Duplicate occurrences
- 0
What this tool helps you do
Detect repeated lines, see separate duplicate-line and occurrence totals, then keep either the first or last occurrence.
How to use Duplicate Line Detector & Remover
- Paste newline-separated values.
- Choose case-sensitive or case-insensitive comparison.
- Inspect the counts, then remove duplicates if appropriate.
Example
Input: Alpha Beta alpha
Result: Alpha Beta (case-insensitive, keep first)
Practical note: Leading and trailing spaces count as part of a line. Use Text Cleaner or Line Tools first when whitespace should not distinguish items.
Supported formats
Plain text typed or pasted into the browser.
Limits and safety
Guests can split up to 20,000 characters per task. The number of resulting segments is not limited. A high technical safety ceiling protects the browser for signed-in members.
Frequently asked questions
Can I use my own delimiter?
Yes. Choose Custom delimiter and enter the exact characters between each segment. It is treated as literal text, not a regular expression.
Is my text uploaded or saved?
No. Splitting happens in this browser tab. The input and results are not uploaded or saved by this tool.