Interactive Remove Duplicate Lines
Paste one item per line and choose an action.
Results
Processed lines (0)
No values.
How duplicate removal works
The tool creates a comparison key for each line, keeps the selected first or last occurrence, and reports the original count, unique count, and duplicates removed. The displayed spelling comes from the retained occurrence.
Capitalization and whitespace
Case-insensitive mode treats Project A and project a as duplicates. Trimming removes surrounding spaces before comparison; it does not rewrite spaces inside a line.
Example
For red, blue, red, and green, preserving the first occurrence returns red, blue, and green in that order. Sorting is a separate optional final step.
Practical input limits
For responsive browser-local processing, each input accepts up to 2,000,000 characters and 50,000 lines. Ordinary 10-line, 1,000-line, and 10,000-line lists are supported without a server round trip.
Private, task-first processing
The transformation runs locally after an explicit action. Input values are not sent to a server, executed as code, or placed in analytics.