| zid | ZooImage Data |
| zil | DMDX ZIL Output Data |
| zim | OpenZIM Archive |
| zimaa | OpenZIM Splitted Archive |
| zimab | OpenZIM Splitted Archive |
| zimac | OpenZIM Splitted Archive |
| zin | ZINDO Input Data |
| zipo | Need for Madness Game Data |
| zis | ZooImage Series Description |
| zit | ZIT File Tracking Repository Data |
| zix | Quicken Data |
| zjv | PARTsolutions 3D Model |
| zkn | Adobe RoboHelp WebHelp Skin Definition |
| zks | ZK Stereo Data |
| zktx | libGDX Compressed Texture Data |
| zkx | ZixCorp Signature Data |
| zlb | Form Z Symbol Library File |
| zlg | e-Surveiller Compressed Log |
| zlic | KeyShot License Data |
| zlog | ZTreeWin Log |
| zma | ZMA Impedance Response Data |
| zmc | ZoneAlarm Quarantine |
| zmesh | Imagine 3D Mesh Data |
| zmf | Zemax Lens Catalog File |
| zmg | ZENworks Desktop Management Image |
| zml | Zooming Markup Language |
| zmm | Zemax Multi-mode File |
| zmt | MOPAC Z-Matrix Molecule Data |
| zmx | Zemax Lens Data |
| zna | Zinio Annotation File |
| zncn | RMCProfile Zinc Neighbours Data |
| znl | Number Lines Lesson Data |
| znm | ZBrush NoiseMaker Data |
| znt | SigmaWin+ Zone Table Data |
| zof | Zemax Object Format File |