| wbu | Samsung PC Studio Backup Data |
| wdz | WinDev Zip Archive |
| webpnp | Web Point-and-Print Cabinet |
| wfz | Amazfit Watch Face |
| wgz | S60 Web Runtime Widget Package |
| whb | CopyTrans iPod Backup Image |
| winuha | UHarc Archive |
| wna | Whitenoise Archive |
| wpb | Windows Phone Device Manager Backup |
| wpress | All-in-One WP Migration Archive |
| wr3 | WRaptor Compressed Archive |
| wra | WRaptor Compressed Archive |
| wrc | FreeArc Archive File |
| wxz | wxWidgets Zipped Package |
| wza | Encryption Wizard Archive |
| wzd | Encryption Wizard Encrypted Individual File |
| wzp | AMP1-16 Update Archive |
| x1z | X1 Search Saved Search Archive |
| xam | Xamarin Package |
| xapk | Compressed Android Package |
| xbw | XBW Compressed Data |
| xdc | DarkCryptTC XDC Encrypted Container |
| xef | WinAce Encrypted Archive |
| xpak | XLN Audio Package |
| xpi | Mozilla XPInstall Package |
| xrec | xRecovery Data |
| xsa | XelaSoft Archive |
| xsoem | XenServer OEM Update Archive |
| xz | XZ Compressed File |
| xzm | Porteus Module |
| yar | YAK Compressed Archive |
| ybs | YBS Compressed Archive |
| yc | YAC Compressed |
| yep | Yamaha Expansion Pack |
| yz | YAC Compressed |