xlsx
SheetJS Spreadsheet data parser and writer
docx
Easily generate .docx files with JS/TS with a nice declarative API. Works for Node and on the Browser.
mammoth
Convert Word documents from docx to simple HTML and Markdown
exceljs
Excel Workbook Manager - Read and Write xlsx and csv Files.
hyperformula
HyperFormula is a JavaScript engine for efficient processing of spreadsheet-like data and formulas