Category

Spreadsheets & File Formats

Most list comparisons start life inside a spreadsheet or a flat file export: two Excel columns, two Google Sheets ranges, a pair of CSV or TSV exports, a JSON payload, a Word document, or a plain text file from Notepad++. These guides cover the format-specific parts — how to copy a column without breaking it, which delimiter to pick, how quoted fields and line endings trip up a naive comparison, and when a full-row comparison is wrong and a single key column is right. The underlying comparison is always the same five operations (only in A, only in B, intersection, union, symmetric difference); what changes between formats is how you get clean, comparable text out of the source file in the first place. Start with the CSV or Excel guide if you're not sure which applies — most spreadsheet and flat-file problems reduce to the same handful of gotchas: header rows accidentally included as data, inconsistent casing between exports, and trailing whitespace that makes identical-looking values fail to match.