Collection of free online tools for CSV and Excel files. Merge, split, subtract, compare, combine, update data, add country codes, and convert between Excel and PDF. The key difference? Every operation runs 100% in your browser. Your files never leave your device, no uploads, no servers, no sign-ups. Just drag, drop, and download. Built for marketers, data analysts, and anyone who works with spreadsheets daily but doesn't want to install software or trust cloud services with sensitive data.