30 File Extensions starting with X
| .X | Stardent AVS X Image |
| .X11 | X Windows System Dump Image |
| .X3F | Raw Image File |
| .XAML | Extensible Application Markup Language |
| .XAR | Xara Image |
| .XBM | X Bitmap Image |
| .XCF | Gimp Bitmap Image |
| .XIF | Xerox DIFF Image |
| .XIM | Ximage |
| .XLC | Microsoft Excel Chart |
| .XLM | Microsoft Excel Macro |
| .XLS | Microsoft Excel Spreadsheet |
| .XLS | Comma Separated Value Database |
| .XLSB | Microsoft Excel Binary Spreadsheet |
| .XLSM | Microsoft Open XML Macro-Enabled Excel Spreadsheet |
| .XLSX | Microsoft Open XML Excel Spreadsheet |
| .XLT | Microsoft Excel Template |
| .XLTM | Microsoft Excel XML Template |
| .XLTX | Microsoft Excel XML Template |
| .XLW | Microsoft Excel Workspace |
| .XM | Extended Module Audio File |
| .XML | DocBook Document |
| .XML | Extensible Markup Language |
| .XP0 | SecretPhotos Puzzle Image |
| .XPI | Firefox Plugin |
| .XPM | X PixMap Image |
| .XSPF | XML Shareable Playlist Format |
| .XV | Khoros Visualization Image file |
| .XWD | X Windows System Dump Image |
| .XXE | Compressed ASCII Archive |