Compare Two Lists

Two lists that should be identical almost never are, and hunting for the odd rows by eye is how afternoons disappear. Put one list on each side, and Compare Two Lists shows which values sit on one side only and which sit on both. Row order plays no part, so a value that moved to another line still counts as a match.

A list can be pasted one item per line or imported from a text file or a spreadsheet, where you choose the worksheet and a single column. Two switches decide whether capital letters and spaces at the edges count as a difference. Every value is read as text, so the product code 00123 stays different from 123. A cleanup step runs find and replace or splits a comma-separated line into rows before the comparison, and repeated entries inside one list get a group of their own.

The comparison runs in the browser tab, and the privacy page says lists and file names are never uploaded or stored. Each result opens to show the lines it came from in the original input. Groups can be copied or downloaded as text, CSV or an Excel workbook. The site sets the ceiling at 100,000 lines and about 5.2 MB per list. It works on distinct values in one column per list and leaves quantities aside.