C File Extensions
Browse file types with extensions beginning with C.
| Extension | File Type | Popularity |
|---|---|---|
| .C | C/C++ Source Code File | 4.1 |
| .C | Lite-C Script | 2.9 |
| .C00 | WinAce Split Archive File | 3.8 |
| .C001 | C001 Source Code | 3.5 |
| .C01 | WinAce Split Archive Part 1 File | 3.4 |
| .C01 | Typhoon Wave Audio File | 2.0 |
| .C02 | WinAce Split Archive Part 1 File | 2.7 |
| .C10 | WinAce Split Archive Part 10 | 3.7 |
| .C2D | WinOnCD Disc Image | 2.8 |
| .C2G | Lexy's Labyrinth Level Pack Index | 1.3 |
| .C2M | Lexy's Labyrinth Level | 1.7 |
| .C2R | Windows Media Center Click-To-Record File | 4.0 |
| .C2U | Texas Instruments CBL 2 OS File | 1.0 |
| .C3 | C3 Source Code | 1.0 |
| .C32 | Syslinux COM32 Module | 3.9 |
| .C3D | Coordinate 3D File | 4.7 |
| .C3D | C3D Model File | 3.5 |
| .C3P | Construct 3 Project | 4.3 |
| .C3Z | OpenQwaq 3D Model File | 3.2 |
| .C4 | JEDMICS Image File | 2.1 |
| .C4D | Cinema 4D Model | 4.3 |
| .C4K | Clonk Key File | 3.2 |
| .C4P | CrossOver Software Installer File | 3.6 |
| .C67 | Composer 670 Module | 2.0 |
| .C93 | Interplay C93 Video | 2.0 |
| .C9R | Cryptomator Encrypted Data | 4.3 |
| .CA | Initial Telnet Cache | 3.0 |
| .CAA | CleanApp Archive | 2.3 |
| .CAA | Chinese Academic Article Link File | 4.0 |
| .CAB | Windows Cabinet File | 3.9 |
| .CACHE | Cache File | 3.8 |
| .CACTION | Automator Converter Action | 3.7 |
| .CAD | BobCAD-CAM File | 4.1 |
| .CAD | Autodesk QuickCAD File | 4.0 |
| .CADC | Corpatla Data Container File | 2.7 |
| .CADOC | Clicker App Document | 2.0 |
| .CADQ | CADQ Ransomware Encrypted File | 2.0 |
| .CAF | Core Audio File | 3.6 |
| .CAF | Class Action Gradebook File | 2.5 |
| .CAF | Cal3D Binary Animation File | 1.8 |
| .CAF | CryENGINE Character Animation File | 3.1 |
| .CAF | Cathy Catalog File | 3.0 |
| .CAFF | Core Audio File | 3.5 |
| .CAFFEMODEL | Caffe Model | 4.2 |
| .CAG | ClipArt Gallery Package | 2.0 |
| .CAH | 5e Companion App Character File | 3.1 |
| .CAJ | Chinese Academic Journal File | 3.1 |
| .CAK | SEGA FILM Video | 2.0 |
| .CAK | WWE 2K20 Game Data Archive | 1.0 |
| .CAL | Calendar File | 4.0 |
| .CAL | CALS Raster Graphic | 2.7 |
| .CAL | 3ds Max Pose Adjustment File | 3.3 |
| .CAL | CryENGINE Character Animation List | 2.0 |
| .CALB | Coolect Album File | 1.0 |
| .CALCA | Calca Document | 3.0 |
| .CALIBRE | Calibre Device Data File | 3.7 |
| .CALS | CALS Raster Graphic File | 3.5 |
| .CAM | CASIO Digital Camera Picture File | 2.6 |
| .CAM | Gerber CAM Job File | 3.3 |
| .CAM | FastCAM CAM File | 3.5 |
| .CAM | MSN Messenger Webcam Recording | 2.0 |
| .CAMERROR | Camtasia Studio Error File | 3.5 |
| .CAMM | espresso Mind Map Document | 2.7 |
| .CAMP | WCS Color Appearance Model Profile File | 3.3 |
| .CAMPACKAGE | Camtasia Package | 2.0 |
| .CAMPAIGN | Wee Tanks! Campaign | 4.5 |
| .CAMPROJ | Camtasia Studio Project | 3.8 |
| .CAMREC | Camtasia Studio Screen Recording | 3.6 |
| .CAMSC | Camtasia Shortcut Set (macOS only) | 2.0 |
| .CAMSHORTCUTS | Camtasia Shortcut Set (Windows only) | 2.0 |
| .CAMTEMPLATE | Camtasia Template | 2.0 |
| .CAMTHEME | Camtasia Theme File | 3.5 |
| .CAMV | Camtasia Video File | 3.5 |
| .CAN | Canon Navigator Fax Document | 3.5 |
| .CAN | Canvas Painting | 3.5 |
| .CANNEDSEARCH | Apple Predefined Search | 3.7 |
| .CAP | Construct Game Development File | 3.1 |
| .CAP | Packet Capture File | 3.2 |
| .CAP | ASUS BIOS Update File | 3.2 |
| .CAP | PASCO Capstone Experiment File | 2.7 |
| .CAP | Capella Score | 2.5 |
| .CAPOBUNDLE | Capo Project | 3.0 |
| .CAPROJ | Construct Project File | 4.0 |
| .CAPT | Capito Data File | 4.0 |
| .CAPX | Construct Compressed Project File | 3.9 |
| .CAPX | Capella CapXML Score | 3.8 |
| .CAR | CAR Archive | 3.2 |
| .CAR | Brew Component Application Resource | 3.4 |
| .CAR | Car Explorer Data File | 3.4 |
| .CAR | Gary Gadget Car File | 3.4 |
| .CAR | Compiled Asset Catalog | 3.7 |
| .CARC | Nintendo Compressed Archive File | 3.8 |
| .CAROTE | Carote Ransomware Encrypted File | 1.5 |
| .CART | BrickLink Exported Cart | 3.5 |
| .CAS | Autodesk Cascade License File | 3.4 |
| .CAS | Total War Model File | 2.9 |
| .CASE | SlipCover Case Template | 2.5 |
| .CASS | Apple II Cassette Tape Program | 2.3 |
| .CAST | Asciicast Terminal Recording | 3.3 |
| .CAT | Advanced Disk Catalog Database | 3.3 |
| .CAT | Windows Catalog File | 3.7 |
| .CAT4D | Cinema 4D Catalog | 2.5 |
| .CATALOG | Spindle Search Catalog File | 1.5 |
| .CATALOG | VLC Media Player Skin Catalog | 1.0 |
| .CATDRAWING | CATIA V5 Drawing | 3.4 |
| .CATPART | CATIA V5 Part File | 3.5 |
| .CATPRODUCT | CATIA V5 Assembly File | 4.1 |
| .CATROBAT | Pocket Code Programming Project | 3.5 |
| .CAUCL | Pocket Game Developer Song | 3.5 |
| .CAUD | Cooked Audio Macro | 1.0 |
| .CAUSTIC | Caustic Project File | 3.3 |
| .CAV | Comodo Virus Definitions File | 3.7 |
| .CAWR | Espresso workreport Document | 2.0 |
| .CB7 | Comic Book 7-Zip Archive | 4.0 |
| .CBA | Comic Book ACE Archive | 3.3 |
| .CBA | CryENGINE Resource Compiler Settings File | 2.3 |
| .CBC | Comic Book Collection | 3.4 |
| .CBDDLP | Chitubox Sliced 3D Model | 4.0 |
| .CBDS | Comic Book DS File | 4.5 |
| .CBF | Calendar Builder File | 3.0 |
| .CBF | ChessBase Game Information File | 2.7 |
| .CBG | CyberGauge Data File | 1.0 |
| .CBG | ChessBase Game Moves File | 3.6 |
| .CBH | ChessBase Database Header File | 3.3 |
| .CBK | Backup Configuration File | 3.6 |
| .CBL | COBOL Source Code File | 3.1 |
| .CBMAP | Containment Breach Map File | 4.3 |
| .CBOARD | Final Cut Pro Color Board Preset | 3.5 |
| .CBOR | Concise Binary Object Representation | 3.0 |
| .CBP | Code::Blocks Project File | 3.5 |
| .CBR | Comic Book RAR Archive | 4.0 |
| .CBS | Code Breaker PS2 Save File | 3.8 |
| .CBS | Comodo Backup Script | 2.3 |
| .CBT | Computer Based Training File | 3.8 |
| .CBT | Comic Book TAR File | 4.0 |
| .CBU | Comodo Backup File | 4.0 |
| .CBV | ChessBase Database File | 3.7 |
| .CBXML | CodeBox Library | 2.0 |
| .CBZ | Comic Book Zip Archive | 3.9 |
| .CBZ | ChessBase Encrypted Database Archive | 2.3 |
| .CC | C++ Source Code File | 3.9 |
| .CC3.SB3 | ClipCC Project | 3.0 |
| .CCA | cc:Mail Archive File | 4.0 |
| .CCA | Multimedia Fusion File | 3.0 |
| .CCB | CopperCube 3D Scene | 3.3 |
| .CCB | CocosBuilder Scene | 1.0 |
| .CCBI | CocosBuilder Binary Scene | 1.0 |
| .CCBJS | CopperCube JavaScript File | 2.3 |
| .CCC | Dev-C++ Code Completion Cache | 2.5 |
| .CCC | Comic Chat Conversation | 3.0 |
| .CCCTASK | Carbon Copy Cloner Task Configuration | 3.5 |
| .CCD | CloneCD Control File | 3.7 |
| .CCD | ClickCharts Diagram | 3.5 |
| .CCF | CryptLoad Container File | 3.0 |
| .CCGAME | XNA Creators Club Game Package | 2.1 |
| .CCH | Corel Chart File | 2.5 |
| .CCH | .NET Security Resolution Cache File | 3.1 |
| .CCI | Citra Cartridge Image | 4.4 |
| .CCI | Compressed Champions' Interlace Bitmap | 3.0 |
| .CCI | Cerbios Compressed ISO | 3.5 |
| .CCIP | Curse Client Install Package | 4.3 |
| .CCLD | Construction Clouds Data File | 2.8 |
| .CCN | Compressed Multimedia Fusion File | 3.3 |
| .CCP | RIB Import Converter Profile | 3.0 |
| .CCP | CodeCharge Studio Page File | 3.0 |
| .CCP | CopperCube JavaScript File | 4.0 |
| .CCR | ASTM Continuity of Care Record | 3.4 |
| .CCR | Comic Chat Room Shortcut | 1.0 |
| .CCS | CodeCharge Studio Project File | 3.8 |
| .CCS | CCS Script File | 3.0 |
| .CCSCC | ClearCase Source Control Info File | 2.0 |
| .CCT | Director Protected Cast Resource | 2.9 |
| .CCX | Click & Create Extension | 2.5 |
| .CCX | Corel Clipart File | 2.0 |
| .CD | CD-i OptImage | 2.6 |
| .CD | Visual Studio Class Diagram | 3.9 |
| .CD2 | Click'N Design 3D File | 3.0 |
| .CD4 | Discus 4 Project | 2.0 |
| .CD5 | Chasys Draw Image File | 3.0 |
| .CDA | CD Audio Track Shortcut | 3.5 |
| .CDB | Symbian Phonebook Database | 3.7 |
| .CDB | Pocket Access Database | 4.0 |
| .CDB | CardScan Contacts Database | 3.3 |
| .CDC | AutoCAD DesignCenter Preview Cache File | 3.8 |
| .CDD | ConceptDraw DIAGRAM Document (Legacy) | 3.6 |
| .CDDA | CD Digital Audio File | 3.5 |
| .CDDX | Circuit Diagram Document | 3.0 |
| .CDDZ | ConceptDraw DIAGRAM Document | 3.3 |
| .CDF | Channel Definition Format | 2.6 |
| .CDF | Common Data Format | 3.2 |
| .CDF | Content Definition File | 2.5 |
| .CDF | Nominal Small Business Accounting Company Data File | 2.8 |
| .CDF | Affymetrix Chip Definition File | 2.7 |
| .CDF | Computable Document Format File (Legacy) | 3.9 |
| .CDF | NetCDF Format File | 3.2 |
| .CDF | CryENGINE Character Definition File | 3.3 |
| .CDF | C.Scope Data Log | 2.0 |
| .CDF-MS | ClickOnce Compiled Manifest File | 3.3 |
| .CDG | Compact Disc Plus Graphics Image | 3.6 |
| .CDI | DiscJuggler Disc Image | 3.6 |
| .CDI | INTEX Output File | 4.3 |
| .CDL | CADKEY Wireframe Design File | 3.4 |
| .CDL | ConceptDraw DIAGRAM Library | 1.4 |
| .CDLX | Adobe Audition CD Layout File | 3.0 |
| .CDLX | ConceptDraw DIAGRAM XML Library | 2.0 |
| .CDM | NTI CD-Maker Image | 3.7 |
| .CDM | Conceptual Data Model | 2.0 |
| .CDM | dBASE Custom Data Module | 2.0 |
| .CDML | Creately Diagram File | 3.0 |
| .CDMM | ConceptDraw MINDMAP Document | 2.3 |
| .CDMP | WCS Device Model Profile | 2.0 |
| .CDMT | ConceptDraw MINDMAP Template | 2.0 |
| .CDMTZ | ConceptDraw MINDMAP Template | 2.0 |
| .CDMZ | ConceptDraw MINDMAP Document | 3.6 |
| .CDO | Crescendo Music Notation File | 4.0 |
| .CDOC | Clicker Document | 3.0 |
| .CDOC | Encrypted DigiDoc File | 3.6 |
| .CDP | Trainz Simulator Content Dispatcher Pack | 4.1 |
| .CDP | CD/Spectrum Pro File | 4.0 |
| .CDP | ConceptDraw PROJECT File | 2.3 |
| .CDP | Sony CD Architect Project | 3.3 |
| .CDP2 | Trainz Classics Content Dispatcher Pack 2 | 2.2 |
| .CDPX | ConceptDraw PROJECT XML File | 3.0 |
| .CDPZ | ConceptDraw PROJECT Document | 3.3 |
| .CDR | CorelDRAW File | 3.8 |
| .CDR | Raw CD Audio Data | 3.5 |
| .CDR | Crash Data Retrieval Data File | 2.9 |
| .CDR | Macintosh DVD/CD Master | 3.5 |
| .CDRAPP | CorelDRAW.app Image File | 3.6 |
| .CDRT | CorelDRAW Template | 2.5 |
| .CDS | ConceptDraw DIAGRAM SlideShow (Legacy) | 3.3 |
| .CDSX | ConceptDraw DIAGRAM XML SlideShow | 2.6 |
| .CDSZ | ConceptDraw DIAGRAM SlideShow | 3.0 |
| .CDT | CorelDRAW Template (Legacy) | 3.3 |
| .CDT | ConceptDraw DIAGRAM Template (Legacy) | 2.0 |
| .CDT | CD-Text File | 3.7 |
| .CDT | Super Mario Maker Course Data | 2.0 |
| .CDTX | ConceptDraw DIAGRAM XML Template | 3.3 |
| .CDTZ | ConceptDraw DIAGRAM Template | 3.0 |
| .CDW | KOMPAS Document | 3.6 |
| .CDX | Compound Index File | 3.9 |
| .CDX | CorelDRAW Compressed File | 3.3 |
| .CDX | ConceptDraw DIAGRAM XML Document | 2.6 |
| .CDX | ChemDraw Exchange File | 3.1 |
| .CDX | Alpha Five Table Index File | 3.9 |
| .CDXL | Commodore CDXL Video | 2.0 |
| .CDXML | ChemDraw XML File | 2.8 |
| .CDXML | Cmdlet Definition XML File | 1.5 |
| .CDZ | Compressed CD Image File | 3.8 |
| .CE | ComputerEyes Image | 3.4 |
| .CEB | Apabi eBook File | 3.6 |
| .CEBX | Apabi XML eBook File | 3.0 |
| .CEC | Studio C Alpha Upgrade File | 3.7 |
| .CED | JVC Camera Video Data File | 3.3 |
| .CEDPRJ | Ashampoo CoverEditor Project | 4.0 |
| .CEF | CenturionMail Encrypted Package | 3.0 |
| .CEF | Class Action Gradebook Elementary File | 4.0 |
| .CEL | Audition Loop | 1.7 |
| .CEL | MicroStation Cell Library | 1.2 |
| .CEL | Battery 3 Drum Cell File | 1.3 |
| .CEL | Affymetrix Probe Results File | 4.0 |
| .CEL | Celestia Script File | 3.3 |
| .CEL | FLIC Animation | 1.0 |
| .CELL | Thinkfree Office NEO Cell Workbook | 3.5 |
| .CELTX | Celtx Project File | 3.3 |
| .CELX | Celestia Script | 3.8 |
| .CEM | Children of the Nile 3D Model | 3.4 |
| .CENON | Cenon Project | 3.8 |
| .CENON~ | Cenon Backup File | 3.0 |
| .CEOL | Bosca Ceoil Song | 3.0 |
| .CER | Internet Security Certificate | 3.3 |
| .CERBER | Cerber Ransomware Encrypted File | 3.3 |
| .CERBER2 | Cerber2 Ransomware Encrypted File | 3.7 |
| .CERBER3 | Cerber Ransomware Virus File | 2.3 |
| .CERTSIGNINGREQUEST | Apple Developer Signing Certificate Request File | 3.7 |
| .CETRAINER | Cheat Engine Trainer File | 4.2 |
| .CEX | SolidWorks Enterprise PDM Vault Export File | 4.1 |
| .CF | Sendmail Configuration File | 4.0 |
| .CF2 | Common File Format File | 3.8 |
| .CFA | Adobe Conformed Audio File | 3.2 |
| .CFA | ComProbe Analyzer Capture File | 3.6 |
| .CFB | Compound Binary File | 3.0 |
| .CFC | ColdFusion Component File | 2.4 |
| .CFD | NortonLifeLock Optimization File | 3.3 |
| .CFF | Common File Format | 3.7 |
| .CFG | Configuration File | 4.2 |
| .CFG | Citrix Server Connection File | 4.2 |
| .CFG | MAME Configuration File | 4.2 |
| .CFG | Wesnoth Markup Language File | 4.1 |
| .CFG | Cal3D Model Configuration File | 4.2 |
| .CFG | LightWave Configuration File | 4.0 |
| .CFG | Celestia Configuration File | 4.2 |
| .CFG | M.U.G.E.N Configuration File | 4.0 |
| .CFG | Source Engine Configuration File | 4.0 |
| .CFGE | Jewel Quest Configuration File | 4.1 |
| .CFL | IMVU Product File | 3.3 |
| .CFM | ColdFusion Markup File | 3.4 |
| .CFM | dBASE Custom Form | 2.0 |
| .CFML | ColdFusion Markup Language File | 2.0 |
| .CFORM | X-Ray Game Data File | 2.0 |
| .CFR | Cross Fire Replay File | 4.2 |
| .CFS | Compact File Set Archive | 4.0 |
| .CFS | CFS Console Program | 2.3 |
| .CFS | Lucene Compound Index File | 3.7 |
| .CFSD | 3DS Mii | 1.0 |
| .CFW2 | Cached Font File | 1.0 |
| .CFX | Flow-Cal Data File | 3.0 |
| .CFXR | Cocoa Sfxr File | 2.0 |
| .CG | Cg Program | 4.1 |
| .CG3 | Cabri 3D Document | 3.8 |
| .CGA | Crytek Geometry Animation File | 2.0 |
| .CGD | Common Grid File | 3.5 |
| .CGF | Crytek Geometry Format File | 3.9 |
| .CGFX | CgFX Shader File | 3.6 |
| .CGI | Common Gateway Interface Script | 3.8 |
| .CGM | Computer Graphics Metafile | 2.7 |
| .CGP | PixelCryptor Encrypted File | 2.4 |
| .CGR | Quest3D Channel Group File | 2.4 |
| .CGR | CATIA Graphical Representation File | 3.5 |
| .CGRP | Pro Tools Clip Group File | 4.0 |
| .CGZ | Linux Drivers Archive | 4.0 |
| .CGZ | Cube Map File | 4.2 |
| .CH | Clipper Header File | 3.4 |
| .CH3 | Harvard Graphics DOS Chart File | 3.0 |
| .CHA | IRC Chat Configuration | 3.5 |
| .CHA | Photoshop Channel Mixture | 2.0 |
| .CHA | Character Layout File | 2.0 |
| .CHAI | Chaimera Artwork File | 4.4 |
| .CHAIT | Chaimera Artwork Template | 4.3 |
| .CHAM | Compiled HAM File | 1.0 |
| .CHARINFO | Nintendo Switch Mii | 2.0 |
| .CHARSET | Character Set | 3.3 |
| .CHART | Guitar Rhythm Chart File | 3.5 |
| .CHAT | IRC Chat Configuration File | 3.7 |
| .CHATALL | ChatALL Backup | 2.0 |
| .CHC | HCFR Colormeter Data File | 3.0 |
| .CHCK | Microsoft Exchange Server Database Check File | 3.4 |
| .CHD | Compressed Hunks of Data File | 3.7 |
| .CHEAT | Navi Cheatsheet | 3.7 |
| .CHEF | Chef Source Code File | 3.7 |
| .CHESSTITANSSAVE-MS | Microsoft Chess Titans Saved Game | 3.9 |
| .CHG | Quicken Online Data File | 4.0 |
| .CHG | Windows Net Logon File | 3.5 |
| .CHIP | Microarray Annotation File | 3.5 |
| .CHITUBOX | Chitubox Project | 3.0 |
| .CHK | Saved File Fragment | 3.9 |
| .CHK | StarCraft Chunk File | 3.2 |
| .CHK | InterCheck Checksum Database | 3.9 |
| .CHK | Netgear Router Firmware File | 3.3 |
| .CHKSPLIT | Archiver Split Checksum File | 2.0 |
| .CHL | WinFast PVR2 Channel List | 3.6 |
| .CHM | Compiled HTML Help File | 3.7 |
| .CHML | Chameleon Encrypted Database File | 2.5 |
| .CHN | Ethnograph Data | 4.0 |
| .CHORD | Song Chords File | 3.1 |
| .CHPROJ | Adobe Character Animator Project | 4.0 |
| .CHR | Borland Character Set | 3.6 |
| .CHR | 3ds Max Characters File | 3.6 |
| .CHR | CryENGINE Character File | 3.8 |
| .CHR | Doki Doki Literature Club! Character File | 4.3 |
| .CHR0 | Wii Model Animation File | 3.1 |
| .CHROMAEFFECTS | Synapse 3 Chroma Configuration | 3.0 |
| .CHRP | Chirp Music File | 1.5 |
| .CHRPARAMS | CryENGINE Character Parameters File | 2.0 |
| .CHS | Windows Chinese Noise-Word List File | 3.7 |
| .CHT | Emulator Cheat File | 3.6 |
| .CHT | Windows Chinese Traditional Noise-Word List File | 3.3 |
| .CHUNK001 | File Splitter Split Archive Part 1 | 3.3 |
| .CHV | ChView Interactive Star Map File | 2.8 |
| .CHW | Compiled Help Index File | 4.0 |
| .CHX | AutoCAD Standards Check File | 4.0 |
| .CI | PolySpace Preprocessed Code File | 2.3 |
| .CI | Windows Content Indexer Catalog File | 4.0 |
| .CIA | CTR Importable Archive | 3.8 |
| .CIB | Luminaire Data File | 4.0 |
| .CID | Navigator Chart Image Description File | 3.0 |
| .CIDB | iTunes CD Information File | 3.7 |
| .CIF | Easy CD Creator Disk Image | 3.9 |
| .CIF | Crystallographic Information File | 3.7 |
| .CIL | Clip Gallery Packaged File | 2.7 |
| .CIMG | CImg Image File | 3.4 |
| .CIN | Kodak Cineon Bitmap Image | 3.1 |
| .CIN | Delphine Software CIN Video | 3.5 |
| .CIN | Champions' Interlace Bitmap | 1.0 |
| .CINE | Phantom Digital Video File | 3.9 |
| .CIP | Cavena Subtitles File | 2.3 |
| .CIPHEREDITOR | Ciphereditor Blueprint | 3.7 |
| .CIR | Micro-Cap Schematic | 4.5 |
| .CIRC | Logisim Circuit File | 3.7 |
| .CIRCUIT | KTechlab Circuit Design File | 3.5 |
| .CIS | CheckInbox Settings File | 2.8 |
| .CISO | Compact ISO File | 3.3 |
| .CIT | Intergraph CCITT Image | 3.3 |
| .CIT | Cite Report Project | 4.2 |
| .CIV5MAP | Civilization 5 Map | 2.8 |
| .CIV5MOD | Civilization 5 Mod File | 3.6 |
| .CIV5SAVE | Civilization 5 Saved Game | 3.5 |
| .CIV5SLN | Civilization 5 Solution File | 3.5 |
| .CJS | CommonJS Code File | 3.3 |
| .CK2 | Crusader Kings II Saved Game | 2.0 |
| .CK3 | Crusader Kings III Saved Game | 3.0 |
| .CK9 | Cook'n Cookbook Backup File | 3.8 |
| .CKAN | Comprehensive Kerbal Archive Network Mod Metadata | 3.5 |
| .CKB | C++ Keyboard Shortcut File | 1.0 |
| .CKB | Cricket Audio Bank File | 3.7 |
| .CKBX | Cricket Audio XML Bank Description File | 2.0 |
| .CKD | KeyCreator Design File | 2.2 |
| .CKD | UbiArt Framework Cooked Asset | 2.5 |
| .CKF | Casio Keyboard File | 2.0 |
| .CKP | SQL Server Checkpoint File | 2.7 |
| .CKPT | PyTorch Lightning Checkpoint | 3.6 |
| .CKT | CircuitMaker File | 3.7 |
| .CKT | KeyCreator Design Template | 2.0 |
| .CL | Cursor Library | 3.5 |
| .CL2 | HY-TEK Meet Results File | 1.5 |
| .CL2ARC | Comic Life 2 Document Archive | 3.8 |
| .CL2DOC | Comic Life 2 Document | 3.3 |
| .CL2LYT | Comic Life 2 Layout File | 2.7 |
| .CL2TPL | Comic Life 2 Template | 3.5 |
| .CL4 | Easy CD Creator 4 Project File | 2.0 |
| .CL5 | Easy CD Creator 5 Saved Project | 3.0 |
| .CLANG | Custom Programming Language Definition | 3.0 |
| .CLARA | Clara Archive | 3.0 |
| .CLARIFY | Clarify Document | 3.2 |
| .CLASS | Java Class File | 4.2 |
| .CLASSLIST | SMART Notebook Class List File | 2.8 |
| .CLB | ICQ Contact List | 2.6 |
| .CLB | COM+ Catalog File | 4.3 |
| .CLD | Canon CD Label Template | 3.5 |
| .CLD | ClamAV Virus Definitions File | 4.0 |
| .CLEO | CLEO Grand Theft Auto Mod File | 4.2 |
| .CLF | Caesium Image List | 4.0 |
| .CLG | Collage Maker Project File | 3.6 |
| .CLG | Windows Catalog File | 3.9 |
| .CLI | Grand Theft Auto Clip Data File | 3.6 |
| .CLIF | Cranelift IR Format File | 3.0 |
| .CLIP | Grand Theft Auto 5 Clip | 3.2 |
| .CLIP | Clip Studio Paint Illustration | 4.0 |
| .CLIPS | Coda Clips File | 3.0 |
| .CLIX | CLIX Command File | 2.0 |
| .CLJ | Clojure Source Code File | 2.0 |
| .CLK | Corel R.A.V.E Project File | 3.5 |
| .CLK | ClickView Video File | 2.8 |
| .CLKB | Clicker Books File | 2.5 |
| .CLKBD | Clicker Board Set | 2.0 |
| .CLKC | Clicker Connect Set File | 3.0 |
| .CLKD | Clicker Docs File | 3.7 |
| .CLKK | Clicker Keyboard | 3.7 |
| .CLKM | Clicker Matching Set File | 3.5 |
| .CLKP | Clicker Object Palette File | 1.5 |
| .CLKS | Clicker Sentences File | 3.0 |
| .CLKT | Clicker Grid Set Template | 2.5 |
| .CLKTK | Clicker Talk Set File | 4.0 |
| .CLKV | Clicker Communicator Vocabulary Set File | 3.0 |
| .CLKW | Clicker Word Bank | 3.0 |
| .CLKX | Clicker Grid Set | 3.5 |
| .CLM | GenePattern CEL Descriptor File | 2.3 |
| .CLM | MagicJack Call Log File | 2.5 |
| .CLP | Windows Clipboard File | 4.0 |
| .CLP | CrazyTalk Clip File | 3.8 |
| .CLP | Finale Clip | 2.8 |
| .CLP | Clipper Compiler Instructions File | 1.0 |
| .CLPI | Blu-ray Clip Information File | 3.8 |
| .CLPKG | Crystal Launcher Package | 2.0 |
| .CLR | Animate Color Set | 2.3 |
| .CLR | CryptLoad Router Information File | 1.4 |
| .CLR | Vue Color Maps File | 1.3 |
| .CLR0 | Wii Color Swapping Animation File | 2.0 |
| .CLS | Program Class File | 3.6 |
| .CLS | LaTeX Document Class File | 3.9 |
| .CLT | Clarity Legal Transcript File | 3.5 |
| .CLT | VisualBoyAdvance Cheat List File | 2.8 |
| .CLW | Visual C++ ClassWizard File | 3.5 |
| .CLX | Ceelox SecureMail Secure Message | 2.0 |
| .CLX | Standard Dictionary File | 2.8 |
| .CM | Cable Modem Configuration File | 4.1 |
| .CM | CLEO Custom Mission | 4.3 |
| .CM0012 | Configuration Management File | 3.6 |
| .CM0013 | Samsung Smart TV Index File | 4.0 |
| .CM10 | CaseMap 10 Case File | 3.0 |
| .CM2 | Poser Camera Set File | 3.5 |
| .CM5 | Clone Manager File | 2.0 |
| .CMA | TM1 Exported Cube File | 3.0 |
| .CMA | OCaml Library | 2.0 |
| .CMA | Coach Activity File | 3.6 |
| .CMAKE | CMake File | 3.4 |
| .CMAP | CmapTools Concept Map File | 3.7 |
| .CMAP | The Escapists Custom Prison Map File | 3.5 |
| .CMAT | Cooked Material | 1.0 |
| .CMATE | ControllerMate File | 3.0 |
| .CMBL | Logger Pro Data File | 3.0 |
| .CMD | Windows Command File | 4.2 |
| .CMD | M.U.G.E.N Character Commands File | 3.2 |
| .CMDB | Ansys CFD Mesh | 4.3 |
| .CME | Crazy Machines Experiment File | 3.0 |
| .CME | Command Multimedia Evidence File | 3.6 |
| .CMF | Creative Music Format | 3.6 |
| .CMF | Cal3D Binary Mesh File | 3.5 |
| .CMF | Connected Backup File | 2.5 |
| .CMI | Compiled OCaml Interface | 2.0 |
| .CML | Chemical Markup Language File | 3.7 |
| .CML | Crazy Machines Lab File | 3.0 |
| .CML | CryptoMailer Encrypted File | 3.0 |
| .CML | OGC Web Map Context Document | 2.0 |
| .CMM | Corel Multimedia Manager Album | 2.5 |
| .CMMP | Camtasia MenuMaker Project | 2.5 |
| .CMMTHEME | CleanMyMac Theme File | 3.0 |
| .CMMTPL | Camtasia MenuMaker Template | 3.0 |
| .CMO | ASUS BIOS File | 3.0 |
| .CMOD | Celestia Model | 3.3 |
| .CMP | Solid Edge Wire Harness File | 2.7 |
| .CMP | Generic CADD Component File | 1.0 |
| .CMP | HotDocs Clause Component File | 3.5 |
| .CMP | Windows Connection Manager Profile | 3.7 |
| .CMP | Concept Matrix Pose | 3.0 |
| .CMPKG | craftersmine Package | 2.0 |
| .CMPROJ | Camtasia macOS Project | 3.0 |
| .CMR | Coach Results File | 2.0 |
| .CMR | U.S. Sectional Chart Map File | 3.7 |
| .CMREC | Camtasia Recording | 2.5 |
| .CMS | Content Management System | 3.5 |
| .CMS | Connection Manager Service Profile | 3.9 |
| .CMS | Car Mechanic Simulator 3D Car Model File | 2.8 |
| .CMTP | CometCHAR Patch | 4.3 |
| .CMV | CorelMOVE Animation | 2.5 |
| .CMV | Electronic Arts CMV Video | 2.0 |
| .CMX | Corel Presentation Exchange Image | 3.8 |
| .CMZ | Compressed Poser Camera Set File | 3.0 |
| .CN1 | CNR Modem Initialization Data File | 3.8 |
| .CNA | Catena Project File | 3.0 |
| .CNC | CNC Machine Tool Path | 3.3 |
| .CNC | PartMaster CNC File | 3.4 |
| .CND | Melco Condensed Embroidery File | 2.8 |
| .CNDX | Avery DesignPro for Mac Label File | 2.5 |
| .CNF | Telnet Configuration File | 4.0 |
| .CNF | MySQL Configuration File | 4.3 |
| .CNG | CryptoNG Encrypted Archive | 4.2 |
| .CNM | NoteMap Outline File | 2.5 |
| .CNS | M.U.G.E.N Character States File | 4.2 |
| .CNT | Help Contents File | 3.6 |
| .CNT | Android Cache File | 3.6 |
| .CNV | Canvas 6-8 Drawing File | 2.6 |
| .CNV | Office Converter File | 3.0 |
| .COB | COBOL Source Code File | 3.0 |
| .COD | Compiled Source Code | 3.9 |
| .COD | Atlantis Word Processor Encrypted Document | 3.5 |
| .CODAPLUGIN | Coda Plug-in | 2.6 |
| .CODASITE | Coda Site File | 3.0 |
| .CODE-WORKSPACE | Microsoft Visual Studio Code Multi-root Workspace | 4.0 |
| .CODERCRYPT | CoderWare Encrypted File | 3.0 |
| .COF | MPLAB COFF File | 3.7 |
| .COFFEE | CoffeeScript JavaScript File | 3.8 |
| .COL | Grand Theft Auto Collision File | 4.2 |
| .COL | Capture One Session File | 4.1 |
| .COL | Bricklink Studio Collision Data | 2.0 |
| .COL | Minecraft: Legacy Console Edition Color Table | 3.0 |
| .COLLAB | Blackboard Collaborate Session File | 3.5 |
| .COLLECTION | Adobe Bridge Collection File | 2.9 |
| .COLORPICKER | Color Picker Plugin | 2.0 |
| .COLORS | Scratch 2.0 Block Colors File | 2.4 |
| .COLORS | Painter Color Set | 4.0 |
| .COLOURSCHEME | Speedy Browser Colour Scheme File | 3.0 |
| .COLZ | Adobe Collage File | 2.0 |
| .COM | DOS Command File | 4.0 |
| .COMFYCAKESSAVE-MS | Comfy Cakes Saved Game | 4.2 |
| .COMIC | Comic Life Comic | 2.4 |
| .COMICDOC | Comic Life Document | 3.6 |
| .COMICLIFE | Comic Life Document | 3.3 |
| .COMMAND | Terminal Command File | 3.9 |
| .COMP | Fusion Composition File | 3.1 |
| .COMPCON | COMP/CON Backup | 2.0 |
| .COMPILED | Compiled Game Resource File | 3.9 |
| .COMPONENT | Mac OS X System Component | 3.2 |
| .COMPOSITEFONT | Windows Composite Font File | 3.4 |
| .COMPOSITIONMODEL | Invantive Composition Data Model File | 3.3 |
| .COMPOSITIONTEMPLATE | Invantive Composition Template | 3.4 |
| .COMPPKG.HAUPTWERK.RAR | Hauptwerk Component Package | 4.0 |
| .COMPPKG_HAUPTWERK_RAR | Hauptwerk Component Package | 3.0 |
| .COMPRESSED | WordCompress Compacted Webpage | 3.3 |
| .CON | Concept Application Source File | 3.6 |
| .CON | Battlefield 1942 Configuration File | 4.0 |
| .CON | COW System Settings File | 3.5 |
| .CONDA | Conda Package | 2.0 |
| .CONF | Unix Configuration File | 3.9 |
| .CONF | Generic Configuration File | 3.9 |
| .CONFIG | Configuration File | 3.9 |
| .CONFIGPROFILE | Apple Configuration Profile | 3.5 |
| .CONFORM | Conformalizer Change List | 3.0 |
| .CONN | Bricklink Studio Connection Data | 2.0 |
| .CONSIS | Sciral Consistency Document | 3.0 |
| .CONTACT | Windows Contact File | 3.9 |
| .CONTI | Conti Ransomware Encrypted File | 3.0 |
| .CONTOUR | Contour Screenplay File | 3.0 |
| .CONTRAPTION | Bad Piggies Contraption | 3.7 |
| .CONTROLS | OpenBVE Keyboard Shortcuts File | 2.8 |
| .COOT | Coot Ransomware Encrypted File | 3.3 |
| .COPF | Copy Operation File | 3.4 |
| .COPRESET | Capture One Preset File | 4.3 |
| .COPY | Sony Ericsson Protected Content | 4.1 |
| .COR | Trimble Corrected SSF File | 1.4 |
| .COR | CorelDRAW Drawing | 2.3 |
| .COS | Capture One Settings File | 3.0 |
| .COS | Creatures CAOS File | 1.5 |
| .COS2 | Pinnacle Studio Cache File | 3.7 |
| .COSESSIONDB | Capture One Session File | 3.0 |
| .COSTYLE | Capture One Style File | 4.0 |
| .COT | Coyote Source Code File | 3.2 |
| .COURSE | Super Mario ReMaker Course File | 3.8 |
| .COV | Fax Cover Page File | 2.9 |
| .COVERAGE | Visual Studio Code Coverage Report | 2.2 |
| .COWPERATION | Cowabunga Custom Operation | 2.0 |
| .COX | Click & Create Extension | 1.7 |
| .CP | Captivate Source File | 3.3 |
| .CP | Xcode C++ Source File | 3.6 |
| .CP3 | Grand Prix 3 Cockpit Shape File | 3.3 |
| .CP9 | ChoicePoint Encrypted File | 2.0 |
| .CPA | CADSTAR PCB Archive File | 4.3 |
| .CPAA | Captivate Shared Action File | 2.0 |
| .CPB | Comicino Studio Project File | 3.2 |
| .CPBITMAP | iOS Wallpaper Image | 1.7 |
| .CPC | CPC Compressed Image File | 3.8 |
| .CPD | Compressed PhotoDefiner Image File | 3.5 |
| .CPD | RoboHelp Cache Project Database | 3.8 |
| .CPDX | Adobe Captivate Storyboard Project | 4.0 |
| .CPE | Fax Cover Page File | 3.0 |
| .CPF | Cab Provisioning Format File | 2.4 |
| .CPF | Cognos Project File | 3.6 |
| .CPF | Caesium Profile | 3.3 |
| .CPF | Archicad Teamwork Draft Preferences File | 1.0 |
| .CPG | StarCraft Campaign File | 2.5 |
| .CPG | Manga Studio Page File | 2.7 |
| .CPG | ESRI Code Page File | 3.5 |
| .CPG | Cool Page Project File | 2.0 |
| .CPG | Motorola Solutions Radio Codeplug | 2.0 |
| .CPGZ | Compressed CPIO Archive | 2.8 |
| .CPH | Corel Print House File | 3.3 |
| .CPHD | CloudChan Pre-processed Hypertext Document | 2.0 |
| .CPI | Codepage Information File | 3.3 |
| .CPI | AVCHD Video Clip Information | 3.5 |
| .CPIO | Unix CPIO Archive | 4.2 |
| .CPK | DTM Test Log File | 4.2 |
| .CPK | CRI Middleware Package | 4.2 |
| .CPK | SEGA FILM Video | 3.7 |
| .CPL | Windows Control Panel Item | 3.7 |
| .CPMZ | Miradi/ConPro Project File | 2.8 |
| .CPN | Age of Mythology Campaign File | 3.9 |
| .CPN | Grim Dawn Default Character File | 2.0 |
| .CPP | C++ Source Code File | 4.1 |
| .CPQ | Compaq OEM Disc Configuration File | 3.5 |
| .CPR | Cubase Project | 3.4 |
| .CPR | Windows Phone Display Settings File | 3.1 |
| .CPR | Adobe Captivate Preferences File | 2.3 |
| .CPR | CPC Plus Cartridge | 2.2 |
| .CPS | Corel Photo House File | 1.7 |
| .CPS | The Powder Toy Save File | 4.4 |
| .CPS | Captivate Styles File | 1.4 |
| .CPT | Corel PHOTO-PAINT Image | 3.5 |
| .CPT | Pocket Slides Presentation | 1.0 |
| .CPT | Compact Pro Archive | 2.8 |
| .CPT | Ccrypt Encrypted Archive | 3.6 |
| .CPT | DTS Compact Audio File | 1.7 |
| .CPTL | Adobe Captivate Project Template | 2.0 |
| .CPTM | Captivate Theme File | 3.0 |
| .CPTX | Adobe Captivate Project | 3.5 |
| .CPU | Virtual CPU File | 3.9 |
| .CPVC | Adobe Captivate Video Composition | 3.8 |
| .CPX | Corel CMX Compressed File | 2.0 |
| .CPX | Rise of Rome Campaign File | 3.7 |
| .CPX | Oracle ADF Binding Context File | 3.8 |
| .CPY | eCopy Desktop File | 2.0 |
| .CPY | 3ds Max Copy Track File | 3.4 |
| .CR | Crystal Source Code | 3.0 |
| .CR2 | Canon Raw 2 Image | 4.0 |
| .CR2 | Poser Character Rigging File | 3.2 |
| .CR3 | Canon Raw 3 Image | 3.4 |
| .CRAFT | KSP Spacecraft File | 4.1 |
| .CRAM | Compressed Alignment File | 2.5 |
| .CRASH | Mac OS X Crash Log File | 3.6 |
| .CRASHED | AbiWord Crash-Saved Document | 2.5 |
| .CRC | Total Commander Checksum File | 3.5 |
| .CRD | Guitar chord File | 3.7 |
| .CRD | Windows CardSpace File | 3.2 |
| .CRDOWNLOAD | Chrome Partially Downloaded File | 4.2 |
| .CRDS | Windows CardSpace Backup File | 3.4 |
| .CRE | Papaya Studio Credits File | 1.0 |
| .CREC | Lync Video File | 2.8 |
| .CREV | Adobe Captivate Commentable SWF File | 4.0 |
| .CRF | Cal3D Binary Materials File | 3.9 |
| .CRL | Certificate Revocation List File | 3.5 |
| .CROP | Crick Software Options File | 2.7 |
| .CRP | Cities: Skylines Colossal Raw Asset Package | 4.1 |
| .CRP | COMOS Report File | 1.8 |
| .CRP | dBASE Custom Report | 4.4 |
| .CRPL | Creeper World 3 Script File | 3.0 |
| .CRS | StepMania Course File | 3.5 |
| .CRT | Security Certificate | 4.1 |
| .CRTR | MultiAd Creator Pro Document | 2.2 |
| .CRTX | Office 2007 Chart Template File | 3.6 |
| .CRV | VCarve Pro Design File | 2.9 |
| .CRW | Canon Raw CIFF Image File | 3.8 |
| .CRWL | Windows Crawl File | 2.7 |
| .CRX | Chromium Extension | 4.1 |
| .CRY | CryENGINE Map File | 3.7 |
| .CRYPT | WhatsApp Encrypted Database | 3.4 |
| .CRYPT | CryptXXX Ransomware Encrypted File | 3.5 |
| .CRYPT1 | UltraCrypter Ransomware Encrypted File | 3.3 |
| .CRYPT1 | WhatsApp Encrypted Database File | 3.6 |
| .CRYPT10 | WhatsApp Encrypted Database File | 3.5 |
| .CRYPT12 | WhatsApp Encrypted Database File | 3.8 |
| .CRYPT14 | WhatsApp Encrypted Database File | 3.5 |
| .CRYPT15 | WhatsApp Encrypted Database File | 3.6 |
| .CRYPT5 | WhatsApp Encrypted Database File | 3.3 |
| .CRYPT6 | WhatsApp Encrypted Database File | 3.4 |
| .CRYPT7 | WhatsApp Encrypted Database File | 3.6 |
| .CRYPT8 | WhatsApp Encrypted Database File | 3.7 |
| .CRYPT9 | WhatsApp Encrypted Database File | 3.3 |
| .CRYPTED | WinOptimizer Encrypted File | 3.2 |
| .CRYPTO | Encrypto Encrypted File | 3.3 |
| .CRYPTRA | Cryptra Encrypted File | 3.7 |
| .CRYSISJMSF | Crysis Saved Game | 4.0 |
| .CRYSISPSF | Crysis Warhead Saved Game | 3.0 |
| .CRZ | Compressed Poser Character Rigging File | 4.4 |
| .CS | C# Source Code File | 4.3 |
| .CS | CLEO Custom Script | 4.2 |
| .CS | ColorSchemer Studio Color Scheme | 3.5 |
| .CS1 | CaptureShop 1-shot Raw Image | 3.7 |
| .CSA | PNA Code Calset File | 2.3 |
| .CSA | Star Stable Online Game Archive | 3.8 |
| .CSAPLAN | SPSS Analysis Plan File | 2.0 |
| .CSB | CRIWARE Sound Bank | 3.5 |
| .CSD | Compact Shared Document | 3.7 |
| .CSD | Manga Studio Scene File | 3.3 |
| .CSD | Steam Game Data Backup File | 3.9 |
| .CSD | POEM / Huskygram / Singer EU Embroidery File | 3.5 |
| .CSF | Content Sealed Format | 2.1 |
| .CSF | Adobe Color Settings File | 3.5 |
| .CSF | Cal3D Binary Skeleton File | 2.0 |
| .CSF | GeoMedia Coordinate System File | 3.6 |
| .CSG | CounterSketch Design Project | 1.8 |
| .CSH | C Shell Script | 3.4 |
| .CSH | Cubase Waveform File | 2.8 |
| .CSH | Photoshop Custom Shapes File | 3.8 |
| .CSHTML | ASP.NET Razor Webpage | 4.1 |
| .CSI | ContentServ Include File | 3.3 |
| .CSI | EdLog Program Data File | 2.3 |
| .CSKIN | CD Art Display Skin File | 3.5 |
| .CSL | CineStyle Color Lookup File | 4.2 |
| .CSM | Character Studio Marker File | 3.3 |
| .CSM | Steam Game Backup File | 3.6 |
| .CSMP | Cooked Audio Sample | 1.0 |
| .CSN | Adobe Code Snippet Document | 2.7 |
| .CSO | Compressed ISO Disk Image | 4.2 |
| .CSO | Compiled Shader Object File | 4.1 |
| .CSP | Concept Server Page | 3.1 |
| .CSP | Caché Server Page | 3.7 |
| .CSPLAN | SPSS Sampling Plan File | 3.5 |
| .CSPROJ | Visual Studio C# Project | 3.9 |
| .CSR | Certificate Signing Request File | 3.5 |
| .CSS | Cascading Style Sheet | 4.0 |
| .CSSAVE | Cooking Simulator Saved Game | 2.0 |
| .CST | ContentServ Template | 2.7 |
| .CST | Canvas Custom Set File | 2.8 |
| .CST | Director External Cast File | 3.5 |
| .CST | Manga Studio Story File | 4.1 |
| .CST | Gary Gadget Plug-in | 2.5 |
| .CST | CatSystem2 Scene Script | 3.5 |
| .CST | Citra Save State | 3.5 |
| .CSUTIL | ColorSync Utility Folder | 3.3 |
| .CSV | Comma-Separated Values File | 3.3 |
| .CSWORLD | Terraria for Android 1.2 World | 2.0 |
| .CSX | Visual C# Script | 3.7 |
| .CSY | Canvas Symbol File | 3.7 |
| .CSZ | Cornerstone Document Template | 2.5 |
| .CT | Cheat Engine Cheat Table | 4.1 |
| .CT | Scitex Continuous Tone Image | 4.0 |
| .CTB | AutoCAD Color-Based Plot Style File | 3.7 |
| .CTB | Cherrytree SQLite Document | 3.0 |
| .CTB | Chitubox Sliced 3D Model | 4.0 |
| .CTBL | CTB-Locker Ransomware Encrypted File | 2.0 |
| .CTBL | Slicer Color Table | 2.0 |
| .CTBODYFITTING | CrazyTalk Animator Actor Fitting File | 2.7 |
| .CTC | Visual Studio Command Table Configuration File | 3.5 |
| .CTD | Cherrytree XML Document | 3.5 |
| .CTEX | Cooked Texture | 2.5 |
| .CTEX | Godot Engine 4 Compressed Texture | 3.5 |
| .CTF | WhereIsIt Catalog | 2.9 |
| .CTF | Content Transformation File | 1.8 |
| .CTF | AVG Update Control File | 2.2 |
| .CTF | PSP Custom Theme File | 3.0 |
| .CTG | Canon Digital Camera Catalog | 3.5 |
| .CTI | OMSI Bus Texture Configuration | 1.0 |
| .CTL | Visual Basic UserControl Object File | 2.9 |
| .CTL | StepMania SMZIP Package Description File | 2.8 |
| .CTM | Star Wars Republic Commando Map File | 3.4 |
| .CTM | CrazyTalk Model File | 2.0 |
| .CTO | Visual Studio Binary Command Table Output File | 3.5 |
| .CTP | CakePHP Template | 3.8 |
| .CTP | CrazyTalk Project File | 3.2 |
| .CTPROJECT | Cartoon Animator Project File | 3.8 |
| .CTRACE | Android System Trace | 3.3 |
| .CTS | CrazyTalk Script File | 3.7 |
| .CTS | TreeSheets Hierarchical Spreadsheet | 3.4 |
| .CTSYM | Visual Studio Command Table Output File | 2.0 |
| .CTT | Messenger Contact List | 3.9 |
| .CTV | Citavi Project | 3.7 |
| .CTV3 | Citavi 3 Project File | 3.0 |
| .CTX | Visual Basic Control Binary File | 3.3 |
| .CTX | Valve ICE Encoded Script | 2.5 |
| .CTX | Cherrytree Password-protected SQLite Document | 3.5 |
| .CTXT | BlueJ Context File | 3.3 |
| .CTY | SimCity City File | 3.0 |
| .CTZ | Cherrytree Password-protected XML Document | 3.5 |
| .CU | CUDA Source Code File | 3.7 |
| .CUB | Analysis Services Cube File | 3.9 |
| .CUB | ISIS Cube File | 3.2 |
| .CUB | Gaussian Cube File | 2.0 |
| .CUB | Spark Casual Engine Package | 2.0 |
| .CUBE | Gaussian Cube File | 3.8 |
| .CUBE | Luminar Lookup Table | 2.0 |
| .CUE | Cue Sheet File | 3.8 |
| .CUE | CDRWIN Cue Sheet | 3.0 |
| .CUI | Autodesk Custom Workspace File | 4.1 |
| .CUID | Baidu SDK File | 1.5 |
| .CUID2 | Baidu Device ID File | 3.8 |
| .CUIX | AutoCAD Custom User Interface File | 4.0 |
| .CUL | Windows Cursor Library | 4.0 |
| .CUR | Windows Cursor Image | 4.3 |
| .CURSOR | KDE Plasma Custom Cursor Specification | 3.0 |
| .CURSORFX | CursorFX Theme File | 3.9 |
| .CURVE | Curve Drawing | 2.0 |
| .CURXPTHEME | CursorXP Theme File | 3.6 |
| .CUS | AutoCAD Custom Dictionary File | 3.4 |
| .CUSTOMDESTINATIONS-MS | Windows Jump List File | 3.1 |
| .CUSTOMTANK | Wee Tanks! Custom Tank | 4.3 |
| .CUT | Dr. Halo Bitmap Image File | 2.8 |
| .CUT | Grand Theft Auto Cutscene File | 2.0 |
| .CV | CodeView Data File | 2.8 |
| .CV5 | Canvas 5 Drawing File | 2.8 |
| .CVA | HP System Software Manager Information File | 3.7 |
| .CVA | Canvas Sequence Set | 2.6 |
| .CVC | cVideo Video | 2.4 |
| .CVD | ClamAV Virus Definitions File | 3.2 |
| .CVD | Bitdefender Virus Definition File | 3.1 |
| .CVD | Canvas X Drawing | 3.5 |
| .CVDSYM | Canvas X Draw Symbol Set | 2.0 |
| .CVDTPL | Canvas X Draw Template | 2.0 |
| .CVF | CPU-Z Validation File | 3.4 |
| .CVG | Calamus Vector Graphic File | 3.0 |
| .CVI | Canvas Image File | 3.0 |
| .CVI | CassiniVision Map Image | 2.0 |
| .CVN | CineVision Encoding Session | 3.2 |
| .CVR | Microsoft Crash Report File | 3.9 |
| .CVS | Canvas 3 Drawing File | 3.1 |
| .CVSD | Continuously Variable Slope Delta Audio | 1.5 |
| .CVSRC | CVS Command File | 3.0 |
| .CVT | Canvas External Tool File | 2.4 |
| .CVW | CaseView Document | 2.0 |
| .CVX | Canvas Drawing | 3.5 |
| .CVXCAD | Canvas X Pro Drawing | 3.0 |
| .CW | CardWorks Template | 2.7 |
| .CW | ClassiCube Map | 3.5 |
| .CWA | Continuous Wave Accelerometer Data File | 3.3 |
| .CWB | Cakewalk Bundle | 4.0 |
| .CWC | Coding with Chrome JavaScript File | 3.0 |
| .CWD | Nonogram Puzzle File | 3.5 |
| .CWF | CorelDRAW Workspace File | 3.3 |
| .CWK | ClarisWorks Document | 3.9 |
| .CWP | Cakewalk SONAR Project | 3.5 |
| .CWPRJ | CanvasWorkspace Project | 2.8 |
| .CWS | Claris Works Template | 2.0 |
| .CWS | ChordWizard Song | 4.0 |
| .CWT | ClarisWorks Texture File | 1.5 |
| .CWT | Cakewalk SONAR Template | 3.6 |
| .CWT | ChordWizard Template | 3.5 |
| .CWW | Crossword Weaver Puzzle File | 2.5 |
| .CWY | ChordWizard Style | 2.0 |
| .CWZ | Circuit Wizard File | 3.8 |
| .CX3 | CMS Recorded Video File | 2.0 |
| .CX5 | Clone Manager XML File | 2.0 |
| .CXA | FMAT Listmode File | 3.0 |
| .CXARCHIVE | CrossOver Bottle Archive | 3.6 |
| .CXD | SimplePCI Data Document | 2.2 |
| .CXF | Coordinates Export Format | 3.7 |
| .CXF | Chemical Exchange Format File | 2.5 |
| .CXF | Cuttlefish Extended Format File | 2.8 |
| .CXF | Picasa Collage File | 3.6 |
| .CXI | FMAT RAW Image | 2.4 |
| .CXI | Nintendo 3DS Executable Image | 3.7 |
| .CXP | CX-Programmer Project File | 3.8 |
| .CXP | FMAT Assay File | 2.7 |
| .CXR | FMAT Plate Results File | 3.0 |
| .CXT | Director Protected Cast File | 2.0 |
| .CXT | CX-Programmer Project Text File | 3.9 |
| .CXX | C++ Source Code File | 3.5 |
| .CYBERDUCKLICENSE | Cyberduck Donation Key | 2.0 |
| .CYBERDUCKPROFILE | Cyberduck Connection Profile | 2.0 |
| .CYBERDUCKSEGMENT | Cyberduck Download Segment | 2.0 |
| .CYG | Home Design Object | 2.0 |
| .CYI | Clustify Input File | 2.0 |
| .CYO | Clustify Output File | 4.0 |
| .CYP | Home Designer Pro Project File | 3.5 |
| .CYP | Home Design Project | 4.0 |
| .CYS | Clustify Summary File | 3.0 |
| .CYS | Cytoscape Session File | 4.0 |
| .CYTOIDLEVEL | Cytoid Level Archive | 3.5 |
| .CYW | Rbot.CYW Worm File | 3.4 |
| .CZD | CAD Zone Drawing | 3.6 |
| .CZI | Carl Zeiss Image Data File | 3.3 |
| .CZIP | ZipGenius CryptoZip File | 3.8 |
| .CZP | ClozePro Archive | 2.8 |
All results listed.