Does my data get uploaded anywhere?
No. Everything runs locally in your browser and nothing is sent to a server.
Is this free to use?
Yes. It is completely free, with no account, no signup, and no usage limits.
Does it work on a phone?
Yes. The page runs in any modern mobile browser, on iPhone and Android alike, with no app to install.
Does it show the items that appear only once?
No, and this trips people up. It shows each distinct item once, whether it appeared once or fifty times. If you want the values that never repeated, run Find Duplicate List Items to see the repeats and remove those from this output.
Are "Apple" and "apple" treated as the same item?
No, the comparison is case-sensitive and both are kept. Convert your list to lowercase before pasting if the case difference is not meaningful.
Why is a line I can see twice not being removed?
The two lines are not identical as strings. The usual causes are a double space inside one of them, or an invisible zero-width character pasted from a web page. Retype one of the lines and the duplicate will collapse.
My list is comma-separated, not one per line. What do I do?
Run it through Change List Separator first to turn the comma list into one item per line, deduplicate it here, then convert it back with Comma Separator.
Are blank lines kept?
No. Empty lines and lines that contain only whitespace are dropped, so the output is a tight list with no gaps.
Is my list private?
Yes. The deduplication happens in your browser, so an export of email addresses, order numbers, or user IDs is never transmitted.