This is useful when you have a list of items — emails, IDs, product names, keywords — and need to remove duplicates before importing into a spreadsheet, database, or script.

Options explained

Case-insensitive: Treats "Apple" and "apple" as the same line. Keeps the first occurrence.

Trim whitespace: Strips leading and trailing spaces from each line before comparing. " hello " and "hello" would be treated as the same.

Sort output: Alphabetically sorts the deduplicated lines A→Z.

Ignore blank lines: Removes all empty lines from the output entirely.