Workbook processing runs locally using bundled scripts, fonts and WebAssembly. Only files you explicitly choose or drop are opened. There are no webpage-reading permissions or content scripts. Workbook bytes, file names, cells, formulas and editing history stay in tab memory. No workbook data is placed in URLs, browser storage or remote requests. No automatic analytics or error reports are sent. Closing or reloading clears working state. Downloads create a separate output file without overwriting the source. Website/support links open only on deliberate action; those website requests are covered by https://workbook.tools/privacy.