| Extension | Summary |
|---|
| .Z | Unix Compressed File |
| .Z00 | Split Zip Archive |
| .Z01 | First Split Zip File |
| .Z02 | Second Split Zip File |
| .Z03 | Third Split Zip File |
| .Z04 | Fourth Split Zip File |
| .Z1 | ZoneAlarm Renamed VB File |
| .Z2 | Z-machine Z-code Version 2 File |
| .Z2F | Zoo Tycoon 2 Object File |
| .Z2S | Zoo Tycoon 2 Saved Game |
| .Z3 | Z-machine Z-code Version 3 File |
| .Z3D | ZModeler 3D File |
| .Z4 | Z-machine Z-code Version 4 File |
| .Z5 | Z-machine Z-code Version 5 File |
| .Z6 | Z-machine Z-code Version 6 File |
| .Z64 | Nintendo 64 Game ROM |
| .Z7 | Z-machine Z-code Version 7 File |
| .Z8 | Z-machine Z-code Version 8 File |
| .Z80 | TI-83 and 84 Plus Calculator File |
| .ZAB | Zipped Audio Book |
| .ZABW | Compressed AbiWord Document File |
| .ZAD | Carmageddon Game Data File |
| .ZAP | FileWrangler Archive |
| .ZBFX | zebNet Backup File Extended |
| .ZBLORB | Z-machine Package Game File |
| .ZDB | EPSQ Database |
| .ZDC | CD Catalog Expert Database File |
| .ZDCT | Adobe Language File |
| .ZDL | Avery DesignPro Label File |
| .ZDP | Avery DesignPro Label File |
| .ZDS | GZDoom Save File |
| .ZED | Zipped GEDCOM Genealogy File |
| .ZEPTO | Zepto Virus File |
| .ZFO | XSL-FO Online Form |
| .ZFSENDTOTARGET | Compressed Folder |
| .ZFX | ZipForm File |
| .ZGM | Zenographics Image File |
| .ZGR | BeatSlicer Groove File |
| .ZHTML | Secure IE Zipped HTML File |
| .ZI | Renamed Zip File |
| .ZIF | Zoomify Image Format File |
| .ZIM | OpenZIM Wiki Archive |
| .ZIP | Zipped File |
| .ZIPX | Extended Zip Archive |
| .ZIX | WinZix Compressed File |
| .ZI_ | Renamed Zip File |
| .ZKS | Pathfinder Kingmaker Game Save File |
| .ZL | Zlib Compressed File |
| .ZL9 | ZoneAlarm Quarantined EXE File |
| .ZLB | Form•Z Symbol Library File |
| .ZM1 | ZoneAlarm Renamed MDA File |
| .ZM2 | ZoneAlarm Renamed MDZ File |
| .ZM3 | ZoneAlarm Renamed NCH File |
| .ZM9 | ZoneAlarm MailSafe Renamed Zip File |
| .ZMA | Impedance File |
| .ZMAP | Zombies Ate My Neighbors Map File |
| .ZMC | ZoneAlarm Quarantine File |
| .ZML | Zooming Markup Language File |
| .ZMV | ZSNES Movie File |
| .ZNO | Zinio Electronic Magazine File |
| .ZON | Collection Building Custom Zone File |
| .ZONE.IDENTIFIER | Windows Zone Identifier File |
| .ZOO | Zoo Compressed File |
| .ZOOM | Zoom Recording File |
| .ZPA | Vielklang Audio Metadata File |
| .ZPF | Form•Z Preferences File |
| .ZPI | Zipped File |
| .ZPL | Zune Playlist |
| .ZPS | Zebra Portable Safe File |
| .ZRTF | Nisus Compressed Rich Text File |
| .ZS | ZenScript File |
| .ZS0 | ZSNES Slot 0 Saved State File |
| .ZS1 | ZSNES Slot 1 Saved State File |
| .ZS2 | ZSNES Slot 2 Saved State File |
| .ZS3 | ZSNES Slot 3 Saved State File |
| .ZS4 | ZSNES Slot 4 Saved State File |
| .ZS5 | ZSNES Slot 5 Saved State File |
| .ZS6 | ZSNES Slot 6 Saved State File |
| .ZS7 | ZSNES Slot 7 Saved State File |
| .ZS8 | ZSNES Slot 8 Saved State File |
| .ZS9 | ZSNES Slot 9 Saved State File |
| .ZSD | Dave Mirra Freestyle BMX Data File |
| .ZSH-THEME | Oh My Zsh Theme |
| .ZSM | Raven Software Game Sound Archive |
| .ZSPLIT | Archiver Compressed Split File |
| .ZST | Zstandard Compressed File |
| .ZSTREAM | Angry Birds Classic Texture File |
| .ZT | Mental Ray Image Depth File |
| .ZTD | Zoo Tycoon Data Archive |
| .ZTF | DVD Label Template File |
| .ZTMP | Steam Compressed Game Resource File |
| .ZTR | DVD Label Template Media File |
| .ZUL | ZK User Interface File |
| .ZVD | ZyXEL Voice File |
| .ZVI | Zeiss Vision Image |
| .ZVPL | Visual Paradigm License File |
| .ZVR | SAFA Media Audio File |
| .ZVT | Photoshop Zoomify Preset File |
| .ZVZ | Possible Virus File |
| .ZW | Zooper Widget Template |
| .ZXP | Extension Manager Package |
| .ZZ | Zzip Compressed Archive |
| .ZZZ | CCleaner Securely Deleted File |
| .ZZZZZ | Ransomware Encrypted File |