| .g | Corel Paradox Format |
| .g00 | Clannad Picture Image |
| .g01 | HEC-RAS Geometry Format |
| .g03 | HEC-RAS Geometry |
| .g1 | Gerber Inner Routing Layer 1 |
| .g10 | Garmin GPS Map |
| .g12 | CAMtastic Mid Layer 12 Gerber Data |
| .g13 | CAMtastic Mid Layer 13 Gerber Data |
| .g14 | CAMtastic Mid Layer 14 Gerber Data |
| .g15 | CAMtastic Mid Layer 15 Gerber Data |
| .g2 | Gerber Inner Routing Layer 2 |
| .g3 | G3 Fax Format |
| .g3a | Casio Prizm Program Format |
| .g3d | GOM ATOS 3D Scan Format |
| .g3f | Zetafax Fax |
| .g3n | Imaging Fax Image |
| .g3p | Casio Prizm Picture Image |
| .g3x | RealFlight Content Format |
| .g4 | GTX RasterCAD |
| .g41 | Commodore 1541 Disk Image |
| .g4b | Sokoban++ Level |
| .g5 | CAMtastic Mid Layer Gerber Data |
| .g64 | C64 Emulator Disk Image |
| .g721 | Raw CCITT/ITU G.721 4-bit ADPCM Sound Format |
| .g723 | Raw CCITT/ITU G.723 ADPCM Sound Format |
| .G723-3 | Raw CCITT/ITU G.723 3-bit ADPCM Sound |
| .g723-5 | Raw CCITT/ITU G.723 5-bit ADPCM Sound |
| .g726 | Raw CCITT/ITU G.726 ADPCM Sound Data Format |
| .g726-2 | G726-2 - Raw CCITT/ITU G.726 2-bit ADPCM Sound |
| .g726-3 | G726-3 - Raw CCITT/ITU G.726 3-bit ADPCM Sound Format |
| .g726-4 | G726-4 - Raw CCITT/ITU G.726 4-bit ADPCM Sound Format |
| .g726-5 | G726-5 - Raw CCITT/ITU G.726 5-bit ADPCM Sound |
| .ga3 | Graphical Analysis Document |
| .gab | Dencom Global Address Book Export |
| .gac | Groove |
| .gad | Geodict |
| .gadgeprj | Gadge It Project Format |
| .gadget | Windows Sidebar Gadget Format |
| .gaf | Total Annihilation Animated Bitmap Format |
| .gai | Adobe SING Glyphlet Manager |
| .gal | GenePix Array List Format |
| .galaxy | Blizzard Starcraft 2 Galaxy Script Format |
| .gallery | SMART Notebook Gallery Format |
| .gallerycollection | SMART Notebook Gallery Collection Format |
| .galleryitem | SMART Notebook Gallery Item Format |
| .gam | Game Format |
| .gambas | Gambas Application |
| .game | Command & Conquer Red Alert 3 Format |
| .gamedata | Sandlot Game Data Format |
| .gameproj | GameSalad Game Project Format |
| .gan | GanttProject Project Plan Format |
| .gap | PhotoImpact Pencil Style |
| .gar | GridGain Archive |
| .gas | Grab-a-Site Project |
| .gau | Microsoft Flight Simulator Gauge Format |
| .gax | Age Of Empires II Save Game |
| .gb | Nintendo Gameboy ROM Image |
| .gb1 | Game Maker Backup Format |
| .gba | Nintendo Game Boy Advance ROM Image |
| .gbap | GLBasic Project Format |
| .gbas | GLBasic Source File |
| .gbaskin | GBA4iOS Controller Skin |
| .gbc | Nintendo GameBoy Colour Emulator ROM Image Format |
| .gbck | Glary Utilities Backup |
| .gbcskin | GBA4iOS Controller Skin |
| .gbd | Great Budget Budget Definition |
| .gbf | Great Budget Fringe Definition |
| .gbh | GigaBar Scheme |
| .gbi | GBurner Disk Image Format |
| .gbk | Delphi Runimage Iblocal Examples Format |
| .gbl | Microsoft Visual Basic Global Definition |
| .gblorb | Interactive Fiction |
| .gbm | Genie Backup Manager Archive |
| .gbo | Gerber Bottom Overlay (silk Screen) |
| .gbp | Gerber Bottom Paste Mask Output Format Format |
| .gbproj | Apple GarageBand Project Format |
| .gbr | GIMP Brush Image Format |
| .gbs | Nintendo Game Boy Music Audio Data Format |
| .gbt | Adobe Photoshop Format |
| .gbx | Nadeo Games Format |
| .gbxml | Green Building XML |
| .gc | GraphClick Format |
| .gc3 | Golden Common Lisp Source Code |
| .gca | GCA Compressed Archive Format |
| .gca3 | GURPS Character Assistant |
| .gca4 | GURPS Character Assistant |
| .gca4base | GURPS Character Assistant |
| .gca4party | GURPS Character Assistant |
| .gccv | PageMaker Filter |
| .gcd | Prassi CD Disk Image Format |
| .gcda | GCC Gcov Profiling |
| .gcdp | Greeting Card Studio Project Format |
| .gcf | Steam Client Grid Cache Format |
| .gcg | GCG 8 Sequence Chemical Format |
| .gch | C++ Precompiled Header |
| .gci | Grand Theft Auto 2 Game Format |
| .gcm | GameCube Image Format |
| .gcno | GCC Gcov Profiling |
| .gco | Genbox Family History Chart Options |
| .gcode | G-code Source |
| .gcp | Spectramap Group Properties |
| .gcrd | GnomeCard VCard |
| .gcs | GameShark SharkSave For GameCube Format |
| .gcsx | Microsoft Office SmartArt Color Variation Package Format |
| .gct | Ocarina Cheat Code Manager Exported Cheat Format |
| .gcw | Microsoft Math Worksheet Format |
| .gcx | Apple Grapher Graph Format |
| .gcz | Compressed GameCube/Wii ROM |
| .gd | GD Library Picture Image |
| .gda | Unix Manual Page Guide |
| .gdb | Database Format |
| .gdbindexes | ArcGIS Geodatabase Index |
| .gdbtable | ArcGIS Geodatabase |
| .gdbtablx | ArcGIS Geodatabase |
| .gdc | Iconics GraphWorx32 |
| .gdd | Gerber Drill Drawing Data |
| .gde | GlobalQSL Graphic Editor |
| .gdf | GUESS Graph Data Format |
| .gdfmakerproject | GDF Editor Project Format |
| .gdh | SmartWare High-low Graph |
| .gdi | Generic Download Install |
| .gdiagramstyle | OmniGraffle Diagram Style Format |
| .gdl | ArchiCAD Geometric Description Language Data |
| .gdm | Bells, Whistles, And Sound Boards Module |
| .gdn | SmartWare Graph Definition |
| .gdoc | Link To Google Docs Web Application Document |
| .gdp | Scrolling Game Development Kit Project |
| .gdq | SmartWare Quick Graph |
| .gdr | Symbian OS Bitmap Font Format |
| .gdraw | Link To Google Drawings Web Application Drawing |
| .gdrive | Gizmo Virtual Drive Format |
| .gds | Graphic Data System Format |
| .gdsp | Astound |
| .gdt | Guitar & Drum Trainer Song Configuration |
| .gdv | SmartWare Graphics Screen Driver |
| .gdw | Jaws Unleashed Data Format |
| .gdx | GAMS Result |
| .gdyn | GIMP Pressure Curves Output |
| .gdz | Genbox Family History Data Initialization |
| .ge2 | Maya 4 GE2 Exporter |
| .ge3 | Mastercam Geometry |
| .ge6 | WinFamily 6 Genealogy |
| .gea | Fifa World Cup Game Data |
| .geb | Dr. Hardware |
| .ged | GEDCOM Family History Format |
| .gedata | Qlucore Omics Explorer Data Format |
| .gedcom | GEDCOM Genealogy Format |
| .gel | Molecular Dynamics Image |
| .gem | GEM Vector Picture Format |
| .gemfile | Ruby RubyGems |
| .gemspec | Ruby RubyGems Specification Format |
| .gen | Ventura Publisher Generated Text Format |
| .generictest | Microsoft Visual Studio Generic Test |
| .genmodel | Eclipse IDE Domain Gen Model |
| .geo | VRML Geography Format |
| .geojson | GeoJSON Format |
| .gep | GeneXproTools Data |
| .geprint | Google Earth Pro Map Setting |
| .ger | German Text/html Info |
| .ges | PINGO GrADS Description |
| .get | Pov-Ray For Windows 3.x |
| .getright | GetRight Unfinished Download |
| .gexf | Graph Exchange XML Graph Format |
| .gf | MetaFont Font Format |
| .gfa | GFA-BASIC Tokenized Source |
| .gfar | Greenfoot JAVA Archive |
| .gfb | GIFBlast Compressed GIF Image Format |
| .gfc | Patton&Patton Flow Charting 4 Flowchart |
| .gfd | GeForms |
| .gff | SignalMap Gene-Finding Format (GFF) Data |
| .gfie | Greenfish Icon Editor Pro Graphic |
| .gfl | GeForms |
| .gform | Link To Google Forms Web Application Form Document |
| .gfp | GreenForce-Player Audio Or Video Format |
| .gfs | Microsoft SharePoint WorkSpace Groove Remote |
| .gft | NeoPaint Font |
| .gfw | GIF World Format |
| .gfx | Genigraphics Graphics Link Presentation |
| .gg | Google Desktop Gadget Format |
| .ggb | GeoGebra Document Format |
| .ggd | GASTAR Output |
| .ggf | GPS Pathfinder Office Geoid Grid |
| .ggg | Green Globs & Graphing Equations Game Record |
| .ggi | GGI |
| .ggm | Green Globs & Graphing Equations Saved State |
| .ggp | GemCom Graphic Format |
| .ggpk | Grinding Gears Package |
| .ggr | GIMP Gradient Format |
| .ggs | Gameboy Emulator |
| .ggt | GeoGebra User-defined Tool |
| .ggz | Garena Skin |
| .ghc | Visual Basic Constant Map |
| .ghd | Geonaute Keymaze Tracklog |
| .gho | Norton Ghost Backup Image Format |
| .ghs | Norton Ghost Backup Format |
| .ght | Ghost Project |
| .ghx | Grasshopper |
| .gi | Prassi DVD Disk Image Format |
| .gi! | GigaSampler/GigaStudio Split |
| .gic | BioWare Aurora Engine Area |
| .gid | Microsoft Windows Help General Index Format |
| .gif | Graphics Interchange File Format |
| .gif2 | Netobjects Fusion Styles Lines |
| .gif89a | GIF 89a Image |
| .gifenx | Egis Encrypted GIF |
| .giff | CompuServe Bitmap Image(Graphics Interchange Format) |
| .gig | GigaSampler/GigaStudio Audio Format |
| .gih | GIMP Animated Brush |
| .gim | Sony Playstation 3 Icon Format |
| .gin | GEMS Engine Control Unit Format |
| .ginspect_prj | GOM Inspect Project Format |
| .gio | Nyquist Midi Test Format |
| .gip | Ghost Installer Package |
| .gir | Gens Plus! Movie |
| .gis | CFS Console Game Installer Settings Format |
| .git | Git Repository |
| .gitattributes | Pro Git Attribute |
| .gitignore | Git Ignore Format |
| .gitkeep | Gitkeep |
| .gjd | 7th Guest Game Archive |
| .gjf | Gaussian Input Data |
| .gkf | GAUSS Engine License |
| .gkh | Ensoniq EPS Family Disk Floppy Format |
| .gko | Gerber Keep Out Layer |
| .gkp | GameKeyboard |
| .gks | Graphical Kernel System Fle |
| .gl | Graphical System For Presentation Animation Format |
| .gl2 | HP Graphics Language Plotter |
| .gla | Sothink SWF Easy Project Format |
| .glad | GenePattern GLAD |
| .glade | Glade Project Format |
| .glb | STK Globe Format |
| .glc | IGIS Data |
| .gld | MPLAB C Compiler Linker Script Format |
| .glf | Space Engine Shader Format |
| .glif | Glyph Interchange Format |
| .glink | Link To Third-party Google Drive Web Application Document |
| .glk | Microsoft SharePoint WorkSpace Groove Shortcut |
| .gll | EASE SpeakerLab Compiled Text |
| .glm | DInsight Modeling Studio 3D CAM Model |
| .glo | Adobe RoboHelp Glossary Format |
| .global | Global Makefile |
| .glos | Microsoft Word For Mac Glossary |
| .glox | Microsoft Office SmartArt Graphic Layout Definitions Package Format |
| .glp | NaviEdit Geoconsult Long Profile |
| .gls | GLScript Format |
| .glu | Cyberglue |
| .glue | GlueMon Audio |
| .glut | OpenGL GLUT |
| .glut2 | OpenGL Glut-3.6 |
| .glut3 | OpenGL GLUT |
| .glx | DataStudio Experiment |
| .gly | Microsoft Word Glossary Format |
| .glz | Crossword Power Tools Crossword Library |
| .gm | Transport Tycoon Game Music Format |
| .gm1 | Heroes Of Might & Magic 3 Saved Game |
| .gm2 | Heroes Of Might & Magic III Saved Game |
| .gm3 | Heroes Of Might & Magic III Saved Game |
| .gm4 | Autologic Bitmap Image |
| .gm6 | Game Maker Project Format |
| .gm81 | GameMaker Data Format |
| .gmanifest | Google Desktop Gadget Control |
| .gmap | Garmin Map Format |
| .gmbck | Game Maker Background Image Format |
| .gmc | Global Mapper Catalog |
| .gmd | Game Maker Stored Game |
| .gme | Interact DexDrive Sony Playstation Memory Card Save |
| .gmf | Robot Arena Design And Destroy Graphic Format |
| .gmi | GPS Tuner Map Calibration Data |
| .gmk | Game Maker Project Format |
| .gml | Geography Markup Language |
| .gmm | Global Mobile Media |
| .gmmod | Game Maker 3D Model Format |
| .gmmp | WCS GMMP Gamut Mapping Profile |
| .gmo | GNU Gettext Machine Object Format |
| .gmp | Geomorph Tile Map |
| .gmr | Game Maker Compiled Game |
| .gmres | Game Maker Resource Format |
| .gms | LibGMS Gesture And Motion Signal Format |
| .gmspr | GameMaker Sprite Format |
| .gmt | Global Mobile Television Multimedia Format |
| .gmv | Gens Movie Capture Format |
| .gmw | Global Mapper Workspace |
| .gmx | GroupMail Message |
| .gmz | GameMaker Complete Source |
| .gnc | Great Notions Embroidery |
| .gnd | Geography Network Document |
| .gne | Flickr PHP Format |
| .gnm | GNM Output Music |
| .gno | GenoPro Genealogy Document Format |
| .gnp | GNXAS GNPeak Output Format |
| .gns | Sound Health Abacus Genesis |
| .gnt | Micro Focus COBOL Generated Code |
| .gnumakefile | GNU Make Makefile |
| .gnutar | TAR Archive Format |
| .go | Google Go Programming Language Source Code |
| .go! | Go!Zilla Unfinished Download |
| .goa | SpiceCAD |
| .gob | LucasArts Game Resource |
| .goc | GEOS GOC Source Code |
| .god | Populous 2 Saved Game Format |
| .gof | GameExchange Raw Object Definition |
| .gofin | Druki Gofin Document |
| .gog | Drumagog Sample |
| .gold | Gnome Desktop |
| .gom | GOpenMol Model Format |
| .goomod | World Of Goo Add-on |
| .gor | Myth: The Fallen Lords Game Data |
| .gorm | Gorm Interface Resource Format |
| .gox | The Games Factory Extension |
| .gp | Guitar Pro |
| .gp1 | Street Atlas GPS Log |
| .gp2 | Gerber Inner Plane 2 (negative) |
| .gp3 | Guitar Pro 3 Project Format |
| .gp4 | Guitar Pro 4 Project Format |
| .gp5 | Guitar Pro 5 Project File Format |
| .gpb | Gerber Bottom Pad Master |
| .gpbank | Guitar Pro Audio Bank Format |
| .gpc | Genie Backup Manager Plugin |
| .gpd | Microsoft Windows Universal Printer Unidrv Minidriver Format |
| .gpe | GP2X Video Game Executable Format |
| .gpf | Ragnarok Online Gravity Re-packed Format |
| .gpg | GNU Privacy Guard Public Keyring Format |
| .gph | Lotus 1-2-3 Graph |
| .gpi | Garmin Point Of Interest Format |
| .gpj | GINT Project Format |
| .gpk | GEOS Compressed Omnigo Format Archive |
| .gpl | GNU Public Licence Text |
| .gpm | Ragnarok Online Update |
| .gpn | GlidePlan Map Document Format |
| .gpp | Serif GraphicsPlus Object Format |
| .gpr | GenePix Results Format |
| .gprj | Gearotic Motion Project |
| .gprx | Geoxa Project Format |
| .gps | GOM Player Skin Format |
| .gpt | Gerber Top Pad Master |
| .gpu | GP2X Utility Program Format |
| .gpw | Autodesk AutoCAD Civil 3D Hydraflow Hydrographs Extension |
| .gpx | Guitar Pro 6 Format |
| .gpz | IBM DB2 Document Manager Document History |
| .gqf | GrafEq Data |
| .gqs | GrafEq Data |
| .gqsx | Microsoft Office SmartArt Style Definitions Package Format |
| .gr2 | Granny 3D Format |
| .gr4 | Pathloss Sharing |
| .gra | Microsoft Graph Chart Format |
| .grade | GradeStat Document Format |
| .grads | PINGO GrADS Data |
| .graffle | OmniGraffle Drawing Format |
| .graphml | Graph Markup Language Format |
| .graphmlz | Compressed GraphML Source Format |
| .grasp | Graphical System For Presentation Animation Format |
| .gray | RAW Gray Samples Bitmap Image |
| .grb | GRIB Meteorological Data Format |
| .grbdropfile | GetRight |
| .grc | Affymetrix Grid Control |
| .grd | Adobe Photoshop Image Ready Gradient Format |
| .grdecl | Eclipse Specific |
| .greenfoot | Greenfoot Project |
| .grey | Raw Image Format |
| .grf | DPlot Graph Format |
| .grg | GreatFamily Graphic Gallery |
| .gri | Petrosys Grid |
| .grib | WMO CBS FM 92-VIII Ext. Gridded Binary Format |
| .grid | GridMove Grid Settings |
| .grk | Gradekeeper Document |
| .grl | Microsoft Windows Update Status Format |
| .grle | Farming Simulator Save Game |
| .grm | NovaLogic Game Facial Expressions |
| .grn | Granny 3D Format |
| .gro | HP-48/49 Grob Graphic Image Format |
| .grob | Graphic Object Bitmap Format |
| .groove | Sony ACID Groove Format |
| .groovy | Groovy Programming Language Script Format |
| .group | Windows Mail Group Format |
| .groupproj | Delphi Project Group Format |
| .groups | WM Keeper CLASSIC Group |
| .growlregdict | Growl Temp Format |
| .growlstyle | Growl WebKit Style |
| .growlticket | Growl Notification Format |
| .growlview | Growl Display Plugin |
| .grp | Microsoft Windows Program Group Format |
| .grr | Gradekeeper Class Roster Format |
| .grs | GetRight Skin |
| .grt | Grapher Template |
| .gru | Geist Preset |
| .grv | Microsoft SharePoint WorkSpace Groove Format |
| .grw | SeeYou Waypoint |
| .grx | GetRight File List |
| .grxml | Grammar |
| .gry | Raw Image (Raw GREY) |
| .gs | Haskell Gofer Script Format |
| .gs0 | Sega Genesis (Megadrive) Emulator Quick Slot 0 Save Format |
| .gs1 | Genecyst Save State 1 |
| .gs3 | Genecyst Game Save State 1 Format |
| .gs4 | Genecyst Saved State Slot 4 |
| .gsa | Microsoft SharePoint WorkSpace Groove Working Space Archive Or Template |
| .gsb | Golden Software Boundary Data Format |
| .gsba | GameSave Manager Save Backup |
| .gsc | Call Of Duty Script Format |
| .gscript | Link To Google Scripts Web Application Script |
| .gscx | Microsoft Office Diagram |
| .gsd | Generic Station Description Format |
| .gsdu | GameSave Manager Database Update |
| .gse | GeneSys Export |
| .gsf | Ghostscript Fonts |
| .gsflib | Game Boy Advance Song Library |
| .gsheet | Link To Google Sheets Web Application Spreadsheet Document |
| .gsi | Golden Software Interchange Format |
| .gsl | GoodSync Job List |
| .gslides | Link To Google Slides Web Application Presentation |
| .gsm | GSM Sound Format |
| .gsp | IMail Server Returned Mail |
| .gsproj | GameSalad Project Format |
| .gsr | Golden Software GIS Format |
| .gsr2 | Golden Software GIS Format |
| .gss | Multi Game Memory Editor Memory Snapshot |
| .gst | MapInfo Geoset Format |
| .gstencil | OmniGraffle Stencil |
| .gsvr | Ghostscript |
| .gsx | Gens Sega Emulator Save State Format |
| .gsym | ArchiCAD For MAC Geometric Description Language |
| .gsz | GeoStudio Project |
| .gszip | GameSalad Market Asset Format |
| .gt | Gold Thread Embroidery Format |
| .gt2 | Graoumf Tracker Music Module (MOD) |
| .gta | Microsoft SharePoint WorkSpace Groove Tool Archive Format |
| .gtable | Link To Google Fusion Tables Web Application Table |
| .gtar | GNU Tar Compressed Archive Format |
| .gtc | Graitec Exchange Format |
| .gte | GigaTrust Protected |
| .gtemplate | OmniGraffle Template |
| .gth | Bibexcel |
| .gthr | Gather Log Format |
| .gti | STRUDL Input |
| .gtkrc | GTK+ Skin Format |
| .gtl | Gerber Top Layer |
| .gtm | GreekToMe Data Format |
| .gto | Quicken Online Data |
| .gtp | Guitar Pro Project |
| .gts | CaptiveWorks PVR Video Recording Format |
| .gtx | Genetica Seamless Texture Format |
| .gui | Dr.Explain Project Format |
| .guide | AmigaGuide Hypertext |
| .guides | The Iconfactory XScope Guides Format |
| .gul | JungUm Global Viewer Korean Language |
| .gus | Universal Score Poster Script |
| .gv | Graphviz DOT Language Format |
| .gvg | Kompass Map |
| .gvi | Google Video Format |
| .gvimrc | GVim Settings Format |
| .gvm | Phantasy Star Online |
| .gvn | GeoVisu Navigation Data |
| .gvp | Google Video Player Google Video Pointer Playlist Format |
| .gvr | GeoVisu Routes |
| .gvt | GeoVisu Tracklogs |
| .gvw | GeoVisu Waypoints |
| .gvy | Groovy Script Format |
| .gw | SWAT Groundwater Input |
| .gwb | GenStat Book |
| .gwf | Benthic Golden |
| .gwi | GroupWise Link Information Format |
| .gwk | GC-Prevue GraphiCode PCB Job Format |
| .gwl | Nanoscribe General Writing Language |
| .gwp | Greetings WorkShop Format |
| .gws | GeoMedia Geoworkspace Format |
| .gwt | SpaceStat Generalized Weights Format |
| .gwv | Groundwater Vistas Packaged Model |
| .gx2 | Generic Cadd |
| .gxa | General CADD Attribute Data |
| .gxc | General CADD Pro Component Data Format |
| .gxd | General CADD Pro Drawing Format |
| .gxf | General CADD Pro Font Data Format |
| .gxh | General CADD Pro Hatch Pattern Format |
| .gxk | Galaxkey File Manager Encrypted Format |
| .gxl | Graph Exchange Language Format |
| .gxm | General CADD Pro Format |
| .gxr | GeneXus Report |
| .gxt | Grand Theft Auto 2 Game Format |
| .gxw | GRASS GIS Workspace Layout Definition |
| .gym | Sega Genesis/Mega Drive Music Logged |
| .gyp | Google Chromium GYP Input Configuration |
| .gypi | Chrome/Chromium Include |
| .gz | GZIP Compressed Archive Format |
| .gz1 | Orgadata LogiKal |
| .gz2 | Misnamed BZ2 Format |
| .gza | Bzip2 Compressed File Archive |
| .gzf | Webcopier |
| .gzi | GZip Compressed Archive |
| .gzip | GNU ZIP Gzip Compressed Archive Format |
| .gzl | Go!Zillalist |
| .gzp | Giants Citizen Kabuto Game |
| .gzquar | BitDefender Quarantine |
| .gzr | GunZ |
