Compare Two Lists
Compare Two Lists is a browser-based utility for checking which values appear in two lists. Paste a column or import a TXT, CSV, or XLSX file, then inspect values found only in A, only in B, or in both lists. Duplicate groups are shown separately. You can trim outer whitespace, choose whether to ignore case, and export results as Excel, CSV, or TXT. Values such as 00123 and 123 remain distinct. Comparison and file reading happen in the browser, and original files are not modified. It compares distinct-value membership, not quantities or entire spreadsheets. It is free and needs no account.