Every online Excel tool makes you upload your file to a stranger's server. SplitMyExcel doesn't. It runs 100% in your browser, so your file never leaves your device — watch the Network tab and you'll see zero uploads. Split a spreadsheet into separate files by any column, merge files, remove duplicates, fix broken CSV encoding, change delimiters, and convert between Excel, CSV and JSON. Works with .xlsx, .xls, .csv and Google Sheets, even millions of rows. No signup, no limits. Free.
