How to compare two lists
Paste one list into each box, one item per line, and the shared items and both differences appear at once. It fits comparing last month roster against this month, removing already contacted people from a send list, or checking whether two systems export the same set of codes.
You get three blocks of output. Items present in both lists, items only in A, and items only in B. Reading a single direction hides either the additions or the removals, so both are always computed, and each block has its own copy button.
Both lists are treated as sets. A value repeated inside one list collapses to a single entry and appears once in the results. The counts on screen are therefore de-duplicated counts and can differ from the raw number of lines you pasted. Shared items and items only in A follow the order they appear in A; items only in B follow the order in B.
Three options control how values are matched. Trimming surrounding spaces and ignoring blank lines are on by default, and case insensitive matching is there when you need it. With case ignored, the spelling of the first occurrence is what shows up in the output.
Frequently Asked Questions
Duplicates collapse into a single entry. The tool treats each list as a set, so a repeated item shows up once in the results and the counts on screen are the de-duplicated counts.
Yes. The intersection, the items only in A and the items only in B are all shown at the same time. Looking at one direction alone hides either the added items or the removed ones, so both are always computed.
The trim option is on by default and handles that. Lists copied out of a spreadsheet or a web page often carry trailing spaces, and with trimming on those values are recognised as equal.