Text Merge

Merge two lists of text line by line with a custom separator.

This tool runs entirely in your browser. Your files are never uploaded to a server.

What this tool does

Combines two lists, one item per line, into a single list by joining each pair of matching lines with a separator you choose.

How to use it

Paste List A in the left box and List B in the right box, one value per line, then set the separator text. The merged result appears below and updates as you edit either list.

Worked example

With List A "apple, banana, cherry" and List B "red, yellow, dark red" (one per line) and the default " - " separator, the output is "apple - red", "banana - yellow", "cherry - dark red" — one merged line per pair.

How mismatched list lengths are handled

The merge always produces as many lines as the longer list. Any line missing from the shorter list is treated as empty, so a three-item List A merged with a two-item List B still produces three lines, with the separator but nothing after it on the last one.

Choosing a separator

The separator can be any text, not just a dash — a comma, a tab-like sequence of spaces, or even an empty string to join values directly. It's inserted between every pair, including on lines where one side is empty.

Limitations

Lines are matched purely by position (line 1 with line 1, line 2 with line 2), not by matching values, so lists must already be in the same order — this isn't a join or lookup by key.

Privacy

Both lists and the merge happen entirely in your browser — nothing is uploaded to a server.

Frequently Asked Questions

What happens if the lists have different lengths?
Missing values are treated as empty, so the merge still completes using the longer list's length, with a trailing separator on short lines.
Does it match items by value or by line position?
By line position only — the first line of List A always merges with the first line of List B, regardless of content, so both lists need to already be aligned.
Can I use something other than a dash as the separator?
Yes, the separator field accepts any text, including commas, multiple spaces, or an empty value to join items with nothing between them.
Is my text sent to a server?
No, both lists and the merged output are computed entirely in your browser.