Interleave lines
Merge two lists or texts by alternating their lines one by one.
Interleave lines
Interleaving is the simple act of merging two lists by taking turns: first line from list A, first line from list B, second from A, second from B, and so on. Paste both lists into the two input panels and the merged result appears instantly. If one list is longer, the leftover lines are appended at the end so nothing is lost. The tool preserves empty lines, spacing, punctuation, and special characters exactly as they appear.
This operation is useful whenever you need to combine parallel data into a single sequence without duplicating either list. Match two columns of names to pair them for a contact roster, merge columns of questions and answers into an alternating Q&A list, layer alternative lines in poetry or song lyrics, or interleave steps from two recipes to run them in parallel. The tally shows the total number of output lines so you can verify the count at a glance and confirm the merge succeeded.
The tool works line by line, treating each line as an indivisible unit. Blank lines count as regular lines and are interleaved just like any other. Windows and Unix line endings are both handled transparently, so whether your text uses CRLF or LF, the result is consistent.
Everything runs in your browser. Your lists never leave your device, so you can safely work with private data, customer records, or confidential lists without uploading anything to a server.