Duplicate List
Expand a list into repeated test data or a predictable pattern while keeping every item and separator under your control.
A QUICK WALKTHROUGH
How to use this tool
- Paste a list up to 100,000 characters and choose how its items are separated.
- Choose the total number of copies, their order, and whether empty items should remain.
- Duplicate the list, review the exact result, then copy it or download a text file.
Two useful repetition orders
Repeat the whole list appends complete copies in sequence. Repeat each item keeps identical items together. Reversing added copies applies only to whole-list order, so the first copy remains exactly as entered while every added copy is reversed.
Literal separators and bounded output
Choose newline, comma, tab, semicolon, or a literal custom separator for both input and output. No regular expression is executed. Empty items are preserved unless you remove them. Input is limited to 100,000 characters, 50,000 parsed items, 100,000 output items, and 500,000 output characters.
GOOD TO KNOW
Common questions
Does the copy count include the original list?
Yes. A copy count of 2 returns the original plus one added copy.
Can I repeat each item before moving to the next?
Yes. Choose Repeat each item. Reverse added copies is unavailable in that order because there is no separate added list to reverse.
Are spaces trimmed from each item?
No. Items are kept exactly as entered. Only newline input normalizes CRLF or CR line endings to LF.