Duplicate List

“Repeat whole list” treats the entire input as one block and concatenates N copies of it. “Repeat each item” walks the list once and emits each item N times before moving on. So for input A, B, C with N = 3: whole-list mode produces A, B, C, A, B, C, A, B, C; each-item mode produces A, A, A, B, B, B, C, C, C.

Yes – both produce exactly (original_count × N) items in total. The two modes only differ in interleaving order, not in how many items end up in the output. An earlier version of this FAQ stated both formulas separately as if they were different – they aren’t; the wording was confusing. Stats line now shows the same total regardless of mode.

The chosen separator is used to split the input into items and then to join the duplicated items back into a string. So if your input is comma-separated, set the separator to comma; the output will also be comma-separated. Six common separators are supported: newline, comma, semicolon, tab, pipe, and space.

10,000. The tool will allow any value in 1-10,000. Above 1,000 a non-blocking info toast tells you the operation may take a moment; the result still renders. A 50,000-item input × 10 repeats produces 500,000 items and runs in well under a second on a modern machine.

Not directly. Workaround: find-and-replace your custom separator with one of the six supported ones (in any text editor) before pasting, then duplicate, then convert back if needed. Adding a free-form separator field is a likely future tweak; the trade-off is escaping rules – e.g. allowing “||” as a separator means we have to decide what “|” means in items.

It produces output identical to the input (split + immediate rejoin with the same separator, no duplication). Useful as a sanity check that your separator setting is correct.

Plain UTF-8 text (.txt), filename duplicated-list.txt. Opens cleanly in spreadsheets, text editors, programming tools, and databases.

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Yes – free, unlimited, no signup, no watermark. Use the output in any context. Attribution to is appreciated but not required.