PHPExcel

PHPExcel is a comprehensive library for reading, writing, and manipulating Excel spreadsheets in PHP, supporting multiple formats like XLS, XLSX, CSV, and more. Developers can create complex spreadsheets with styled cells, formulas, charts, images, and multiple sheets programmatically. It also supports reading existing files, iterating through cells, applying data validation, and converting between formats. Because it handles the details of Excel file structures—including relationships, themes, and various metadata—users don’t need to manage proprietary file internals themselves. The API allows for cell access using row/column indexes or column letters, batch updates, and streaming writes to reduce memory usage. As a mature library, it’s used in reporting, migrations, invoice generation, and any scenario where dynamic, server-side spreadsheet generation is needed in PHP applications.