| File extension | The full name of the file |
|---|---|
| File extension U | Subsampled Raw YUV Bitmap Image |
| File extension U00 | The Price Is Right 2010 Game |
| File extension U01 | Barudan Embroidery |
| File extension U08 | UFile Data |
| File extension U10 | UFile 2010 Tax Return Format |
| File extension U11 | UFile 2011 Tax Return Format |
| File extension U12 | UFile 2012 Tax Return Format |
| File extension U255LAW | Exponential 8-bit Sound |
| File extension U2CAR | NFS:U2 Car |
| File extension U32 | Authorware Cover |
| File extension U3D | Universal 3D Format |
| File extension U3I | U3 Application Information Format |
| File extension U3P | U3 Platform Install Format |
| File extension U8 | Lemings 3D Audio Format |
| File extension U96 | EasyZip Temporary |
| File extension UAE | WinUAE Configuration |
| File extension UAL | Entrust Unattended Login Credentials |
| File extension UAP | SIMATIC WinCC User Archive Export |
| File extension UAQ | Microsoft Windows Action Queue |
| File extension UAS | Ulead PhotoImpact Backup |
| File extension UAV | OpenPilot UAV Settings |
| File extension UAX | Unreal Audio Format |
| File extension UB | Unsigned Byte Audio Format |
| File extension UBIFS | Linux UBIFS Image |
| File extension UBJ | Universal Binary JSON Fiile |
| File extension UBM | IPhoto Mtwain Install |
| File extension UBOX | Universe Sandbox Saved Data Format |
| File extension UBR | IIS WCAT Configuration |
| File extension UC | UnrealScript Class |
| File extension UC2 | UltraCompressor II Compressed Archive Format |
| File extension UCCAPILOG | Microsoft Windows Live Messenger UCC API Log Format |
| File extension UCD | Prosa Diagram |
| File extension UCE | Microsoft Windows XP System32 Format |
| File extension UCF | WebEx Universal Communications Format |
| File extension UCI | UFS Explorer Backup Format |
| File extension UCL | Unreal Tournament Cache Format |
| File extension UCLS | ObjectAid UML Explorer Class Diagram |
| File extension UCM | Urban Chaos Game Format |
| File extension UCP | SmartWare Communications Profile |
| File extension UCR | MicroSim PCBoard Unrouted Nets Report |
| File extension UCS | Homeworld Localized Unicode Strings |
| File extension UCSETTINGS | Universal Converter Settings |
| File extension UCT | UC Browser Theme Format |
| File extension UCV | Universal Converter Conversion |
| File extension UCX | Rational XDE |
| File extension UD | OmniPage User Dictionary |
| File extension UDA | ZEMAX Model Data |
| File extension UDB | Dynamics AX User Database Format |
| File extension UDC | Adobe User Dictionary Format |
| File extension UDCX | Microsoft Office Universal Data Connection Format |
| File extension UDEB | Debian Package Format |
| File extension UDF | Universal Disk Format |
| File extension UDG | UDraw(Graph) |
| File extension UDI | CorelDRAW Draw Script Textures Bitmap |
| File extension UDID | Google Android Unique Device IDentifier |
| File extension UDIF | Apple Mac OS X Universal Disk Image Format |
| File extension UDK | Unreal Map Format |
| File extension UDL | Microsoft Data Link Format |
| File extension UDM | MapView User Module |
| File extension UDO | Moray UDO 3D |
| File extension UDP | Corel VideoStudio Scene Information |
| File extension UDS | FIMware Database Format |
| File extension UDW | Raw Unsigned DoubleWord (32-bit) Data |
| File extension UDX | PI Expert Design Software |
| File extension UEA | Protector Suite QL Format |
| File extension UEED | Uconomix Encryption Engine Encrypted Directory |
| File extension UENC | UltraEdit Encrypted Text |
| File extension UES | Ulead Photo Explorer Slide Show |
| File extension UEW | UltraEdit Wordfile |
| File extension UEZ | Ulead COOL 3D Graphics |
| File extension UFA | GIF Animator Animation Object Information |
| File extension UFC | SATURN Suite |
| File extension UFDR | UFED Physical Analyzer Report Package |
| File extension UFF | DataWave SciWorks Physiological Data |
| File extension UFI | UFOCaptureV2 |
| File extension UFO | Ulead PhotoImpact Object Format |
| File extension UFP | Ulead Photo Project |
| File extension UFR | Ultra Fractal Format |
| File extension UFS | FreeBSD PC-BSD Unix File System Format |
| File extension UFSUZIP | FreeBSD Compressed Unix File System Format |
| File extension UFX | Ultimate 3D Game Engine Material |
| File extension UGD | Need For Speed Underground |
| File extension UGR | Apophysis Gradient |
| File extension UHA | UHARC Compressed Archive |
| File extension UHH | Eurotherm Hydra History Encrypted |
| File extension UHS | Universal Hint System Binary |
| File extension UHTM | Unreal Tournament |
| File extension UHTML | UHTML Document Format |
| File extension UI | User Interface Format |
| File extension UIBAK | UltraISO Backup Disk Image |
| File extension UIC | COCO Unit ICon |
| File extension UID | IBM Voice Type Users |
| File extension UID-ZPS | Zoner Photo Studio Picture Autobackup |
| File extension UIF | MagicISO Universal Image Format |
| File extension UIL | IBM AIX User Interface Language |
| File extension UIN | ICQ 2001 Saved ICQ Contact Information |
| File extension UIR | LabWindows User Interface Resource |
| File extension UIS | WindowBlinds Personality Format |
| File extension UIT | UIX XML Template |
| File extension UIX | UiXML Page |
| File extension UIZ | Spybot Search & Destroy Updater |
| File extension UK | English (British) Language Translation |
| File extension UKA | Fifa World Cup Game Data |
| File extension UKS | Microsoft Works |
| File extension UKX | Unreal Tournament Animation Format |
| File extension UKY | UltraMixer Licence Key |
| File extension ULAW | Raw CCITT/ITU G.711 US Telephony Audio Format |
| File extension ULB | COBOL Unisys Library |
| File extension ULD | Unified Luminaire Datafile |
| File extension ULF | Universal List Format |
| File extension ULP | EAGLE Script |
| File extension ULS | NetMeeting User Location Service Format |
| File extension ULT | Ultratracker Music Module (MOD) Format |
| File extension ULW | U-Law Audio Format |
| File extension ULYS | Ulysses Project |
| File extension ULZ | USBlyzer Data Capture Format |
| File extension UMB | MemMaker Backup |
| File extension UMD | UMD Mobile Ebook |
| File extension UMF | MediaHolder Media Format |
| File extension UML | Visual UML Class Diagram & Model Format |
| File extension UMLCLASS | Java UML Class Model Format |
| File extension UMLX | Visual UML XML Model |
| File extension UMM | Unified Molecular Modeling |
| File extension UMOD | Unreal Tournament MOD Installation Package Format |
| File extension UMP | UModel Project |
| File extension UMR | MyEclipse UML Model Repository |
| File extension UMS | Rune 3D Mesh Format |
| File extension UMX | Deus Ex Format |
| File extension UNA | SIMS Unauthorized Data |
| File extension UNAUTH | SiteMinder Unauthorized Message Format |
| File extension UNCOMPRESSED_SIZE | Singularity Game |
| File extension UNF | Btreive Unformatted |
| File extension UNI | UniMOD/MikMOD Music Module Format |
| File extension UNITXT | YS FLIGHT Language |
| File extension UNITY | Unity Scene Format |
| File extension UNITY3D | Unity Scene Web Player Format |
| File extension UNITYPACKAGE | Unity Package Format |
| File extension UNITYPROJ | Unity 3D Project |
| File extension UNIT_VARIANT | Total War Unit Variant Settings |
| File extension UNIX | Unix |
| File extension UNK | UVProbe Format |
| File extension UNKNOWN | Unknown File Extension |
| File extension UNL | Garmin MapSource Unlock Format |
| File extension UNQ | ACT! 3.0 Email Message Attachment |
| File extension UNR | Unreal Map Format |
| File extension UNS | Visual Navigation Suite Export Or Import Settings |
| File extension UNT | AutoCAD Unit Definition Format |
| File extension UNUSED | Photoline 4 Defaults |
| File extension UNV | BusinessObjects Universe |
| File extension UNX | Unix Text Format |
| File extension UOF | Uniform Office Format |
| File extension UOL | PhotoImpact Clipart Image |
| File extension UOP | Unified Office Format Presentation Format |
| File extension UOS | Unified Office Format Spreadsheet Format |
| File extension UOT | Unified Office Format Text Format |
| File extension UPC | Ultimate Paint Component |
| File extension UPD | Update Format |
| File extension UPDATE | ISAPI Update Format |
| File extension UPDATR | IConomy Update Format |
| File extension UPDF | UltraPdf Publication |
| File extension UPF | Nokia Phone Digital Photo Format |
| File extension UPG | Firmware Upgrade Format |
| File extension UPI | Ulead PhotoImpact Plugin |
| File extension UPJ | Ulead Project |
| File extension UPK | Unreal 3 Game Data Package Format |
| File extension UPK0 | Metro 2033 Game |
| File extension UPL | StarMoney Agent Download |
| File extension UPM | PenMail |
| File extension UPO | DBASE Compiled Update Data |
| File extension UPOI | IGO Points Of Interest Format |
| File extension UPP | Ghostscript Uniprint Unified Printer Parameter |
| File extension UPR | FileMaker User Spelling Dictionary |
| File extension UPS | Microsoft Works |
| File extension UPX | Ultimate Packer For EXecutable Format |
| File extension UPZ | StarMoney Agent Download |
| File extension UQM | The Ur-Quan Masters Archive Format |
| File extension URC | Unicenter Remote Control |
| File extension URD | Ultra Recall Database |
| File extension URD-JOURNAL | Ultra Recall Journal Update |
| File extension URF | AppFace Skin |
| File extension URL | Internet Shortcut - URL - Uniform Resource Locator |
| File extension URLS | GetRight Internet Shortcuts List |
| File extension URL_ | Internet Shortcut - URL - Uniform Resource Locator |
| File extension URP | Universal Report |
| File extension URQ | Review QuickChart Chart |
| File extension URR | Uniface Signatures Format |
| File extension URS | ControlDraw User Requirement Specifier |
| File extension URT | Utah Run-Length Encoded Bitmap Image Format |
| File extension US | English Language Translation |
| File extension US? | Microsoft Word Font |
| File extension USA | Microsoft Office Headers Format |
| File extension USB | SiSoftware Sandra |
| File extension USC | USC Module Definition |
| File extension USECASEDIAGRAM | Microsoft Visual Studio Use Case Diagram |
| File extension USEQ | USeq Genome Data Format |
| File extension USER | Microsoft Visual Studio Project User Options Format |
| File extension USERPROFILE | Norton Antivirus User Profile Format |
| File extension USERTILE-MS | Microsoft Windows 8 Release Preview User Tile Format |
| File extension USF | Nintendo Ultra 64 Sound Format |
| File extension USFLIB | Nintendo 64 Song Library Format |
| File extension USG | PC-Doctor For Windows |
| File extension USH | Creston SIMPL Windows |
| File extension USI | UsiXML UI Description |
| File extension USL | ProWORX Nxt USL Loadable |
| File extension USM | USM Game Video Format |
| File extension USP | PageMaker Printer Font |
| File extension USR | FileMaker Pro Runtime Engine Database Application |
| File extension USS | WinUAE Saved State |
| File extension UST | WiFi SiStr Exported User Theme Format |
| File extension USTAR | Uniform Standard Tape Archive Format |
| File extension USX | Unreal StaticMesh (hardware Brushes) Format |
| File extension UT2 | Unreal Tournament Map Format |
| File extension UT2MOD | Unreal Tournament 2003 MOD Installation Package Format |
| File extension UT3 | Unreal Tournament 3 Map Format |
| File extension UT4MOD | Unreal Tournament 2004 MOD Installation Package Format |
| File extension UT8 | Ghost Master Language Format |
| File extension UTB | µTBackup Backup |
| File extension UTC | BioWare Aurora Game Engine Creature Format |
| File extension UTD | BioWare Aurora Game Engine Door |
| File extension UTE | BioWare Aurora Game Engine Encounter |
| File extension UTF8 | Unicode UTF-8 Encoded Text |
| File extension UTI | Spybot - Search & Destroy Includes |
| File extension UTL | QuickBooks Data |
| File extension UTM | BioWare Aurora Game Engine Store |
| File extension UTP | BioWare Aurora Game Engine Placeable Object |
| File extension UTPART | µTorrent Unfinished Download |
| File extension UTS | Spybot - Search & Destroy Include |
| File extension UTT | BioWare Aurora Engine Trigger |
| File extension UTW | Unity Whirld Format |
| File extension UTX | Unreal Texture Format |
| File extension UTXT | Unicode Text Format |
| File extension UTZ | UIQ Theme Package |
| File extension UU | Uuencoded (compressed) File Archive (ascii) |
| File extension UUD | UUDecoded Format |
| File extension UUE | UUEncoded Format |
| File extension UUS | Ultra Utility Skin |
| File extension UV2 | µVision Project |
| File extension UVCAB | UVScreenCamera Films |
| File extension UVF | Uncertain Value Format |
| File extension UVNTS | UVScreenCamera Notes |
| File extension UVPROJ | µVision4 Project |
| File extension UVR | UVR Mesh |
| File extension UVS | UVScreenCamera Segments |
| File extension UVSEG | UVScreenCamera Segments |
| File extension UVW | 3D Studio MAX UVW Coordinates |
| File extension UVX | Unreal Tournament Saved Game |
| File extension UW | Unsigned Word (16-bit) Music Format |
| File extension UWF | UltraTracker WaveSample Music Format |
| File extension UWL | Corel WordPerfect User Word List Format |
| File extension UXDC | Microsoft Excel Data Retrieval Service Connection |
| File extension UXF | UMLet UML EXchange Format |
| File extension UXX | Unreal Tournament 2003 Cache Format |
| File extension UXY | Barudan Embroidery Outline |
| File extension UYVY | YUV 16-bit Image Format |
| File extension UZ2 | Unreal Tournament Compressed |
| File extension UZE | UltimateZip Compressed Archive |
| File extension UZIP | FreeBSD Compressed Disk Image Format |
| File extension UZY | Backdoor.Sokacaps |
File extensions in alphabetical order: U
The list of file extensions, sorted alphabetically, beginning with the letter U