Merge lists
Combine two lists into one, with optional deduplication and sorting.
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Merge lists
Paste one list into each panel, one item per line, and get a single combined list back. It is the fastest way to fold two subscriber exports into one mailing list, pool keyword sets from two research sessions, join product codes from two suppliers, or stitch a backlog from two spreadsheets together without opening a spreadsheet at all.
Two merge modes cover the usual jobs. "Append B after A" puts the second list underneath the first and keeps both in their original order — the safe default when the lists are unrelated. "Alternate items" interleaves them A, B, A, B, which is what you want when the two lists are parallel, for example names and their matching codes destined for a round-robin rota. If one list is longer, its leftover items follow at the end rather than being dropped.
Removing duplicates is on by default: the first occurrence of a value wins and later copies disappear, so an item present in both lists appears once. Matching is exact, which means "Apple" and "apple " are two different items — run the case converter or a whitespace cleanup first if that matters to you. Sorting orders the finished list alphabetically and handles accented characters correctly. Dropping empty lines removes blank and whitespace-only rows before anything else happens, so a stray newline at the end of a paste cannot become an item.
Everything runs inside your browser and neither list is uploaded anywhere, which makes the tool safe for customer records or internal data. The tally under the output shows how many items each list held and how many survived the merge, updating live as you type.