JExcel requires at least Java 1.4 and Microsoft Excel 2000 to work properly.Therefore, the minimal hardware requirements for running JExcel correspond to the requirements of the particular version of Java and Microsoft Excel.

JExcel requires Microsoft Excel 2000 or higher to be installed in the client environment.

JExcel uses OLE/COM to perform remote procedure calls to Microsoft Excel object model. Only the Microsoft Windows implementation of COM is supported. Therefore, JExcel is Windows-only and not supported on Linux or OS X.

JExcel provides full access to the Excel Object model for any version of Microsoft Excel. The capabilities of JExcel are limited by the capabilities of the Excel Object model of the particular version of Microsoft Excel.

The maximal number of rows and columns on a worksheet depends on the format of the Excel workbook. JExcel is capable to read and write OpenXML workbooks if and only if the version of Microsoft Excel installed in the current environment is capable to work with them.

Some issues related to the conflicts with various add-ins and macros were reported. In all of the reported cases, the cause of the issue was in improper COM and VBA memory management. In general case, such issues are not reproducible after disabling Excel add-ins and fixing memory management issues in macros.