| .WA | Open Source | Pakatut tiedostot | Windows Addon Archive | Win Toolkit | Open Source |
| .WA2 | Midnight Synergy | Pelitiedostot | Wonderland Adventures Custom Adventure File | Subspace Continuum | Open Source |
| .WAV | Microsoft Corporation | Äänitiedostot | WAVE Audio File | ModPlug Player | Open Source |
| .WB | Electronic Arts | Pelitiedostot | FIFA 2000 Game Data | Freelang | Open Source |
| .WB2 | Threefold Photos, Inc. | Rasterikuvatiedostot | Webshots Picture File | Ultimate Webshots Converter | Open Source |
| .WBC | Threefold Photos, Inc. | Rasterikuvatiedostot | Webshots Collection File | Ultimate Webshots Converter | Open Source |
| .WBD | Threefold Photos, Inc. | Rasterikuvatiedostot | Webshots Picture File | Ultimate Webshots Converter | Open Source |
| .WBF | Microsoft Corporation | Sovelluskehittäjän tiedostot | Microsoft Windows Batch File | PSPad | Open Source |
| .WBZ | Threefold Photos, Inc. | Rasterikuvatiedostot | Webshots Download Picture File | Ultimate Webshots Converter | Open Source |
| .WCR | Open Source | Asetustiedostot | Ergane Configuration File | Ergane | Open Source |
| .WDF | Workshare | Datatiedostot | Workshare Compare DeltaFile | WiiJManager | Open Source |
| .WEAP | id Software | Pelitiedostot | Quake 3 Engine Weapon File | AbiWord | Open Source |
| .WEBARCHIVE | Apple | Web-tiedostot | Safari Web Archive | WebArchive Extractor | Open Source |
| .WEBM | Google | Videotiedostot | WebM Video File | Eltima Elmedia Player | Open Source |
| .WEBP | Google | Rasterikuvatiedostot | Google Image File Format | IrfanView | Open Source |
| .WGM | Open Source | Pelitiedostot | Chalk Game Data | Chalk | Open Source |
| .WGT | Interscape | Datatiedostot | IMPS Data File | Xwindow Neuro Bio Clusters | Open Source |
| .WHTT | Open Source | Web-tiedostot | HTTrack Website Copier File | HTTrack | Open Source |
| .WI | Open Source | Rasterikuvatiedostot | Wavelet Image | DjVu Reader | Open Source |
| .WIM | Microsoft Corporation | Levyn kuvatiedostot | Windows Imaging Format File | ExtractNow | Open Source |
| .WINGS | Open Source | 3D-kuvatiedostot | Wings 3D File | Wings 3D | Open Source |
| .WK! | IBM | Työkirjatiedostot | Lotus 1-2-3 Spreadsheet | Gnumeric | Open Source |
| .WK1 | IBM | Datatiedostot | Lotus Worksheet | Gnumeric | Open Source |
| .WK4 | IBM | Datatiedostot | Lotus Lotus 1-2-3 V4 Worksheet | Gnumeric | Open Source |
| .WKB | Corel | Tekstitiedostot | Corel WordPerfect Document | PostGIS | Open Source |
| .WMA | Microsoft Corporation | Äänitiedostot | Windows Media Audio File | Eltima Elmedia Player | Open Source |
| .WML | Syncro Soft | Web-tiedostot | Wireless Markup Language File | AbiWord | Open Source |
| .WMV | Microsoft Corporation | Videotiedostot | Windows Media Video File | Eltima Elmedia Player | Open Source |
| .WN | WN | Web-tiedostot | WN Web File | WN | Open Source |
| .WOFF | Open Source | Fonttitiedostot | Web Open Font Format File | FontForge | Open Source |
| .WOW | Open Source | Äänitiedostot | Grave Composer Music Module | OpenMPT | Open Source |
| .WOWPROJ | Open Source | Sovelluskehittäjän tiedostot | AddOn Studio Project File | Addon Studio for World of Warcraft | Open Source |
| .WPB | PGN Inc. | Rasterikuvatiedostot | OpenCanvas 1.1 Image | Windows Phone Device Manager | Open Source |
| .WPJ | Watcom International Corporation | Harvinaiset Tiedostot | Watcom C/C++ Project | Watcom C/C++ | Open Source |
| .WPT | Corel | Tekstitiedostot | WordPerfect Template | Cube 2 Sauerbraten | Open Source |
| .WR! | IBM | Työkirjatiedostot | Lotus 1-2-3 Spreadsheet | Gnumeric | Open Source |
| .WRD | Open Source | Tekstitiedostot | COREX Manually Verified Word Segmentation Data | COREX | Open Source |
| .WRL | Unknown Developer | 3D-kuvatiedostot | VRML World | FreeWRL | Open Source |
| .WRZ | Parallel Graphics | 3D-kuvatiedostot | Compressed VRML World File | FreeWRL | Open Source |
| .WS | MicroPro International Corp. | Tekstitiedostot | WordStar Document | OpenEmu | Open Source |
| .WSC | Open Source | Pelitiedostot | WonderSwan Color Game ROM | Oswan | Open Source |
| .WSIM | Open Source | Web-tiedostot | FirstStop WebSearch Import Module | FirstStop WebSearch | Open Source |
| .WSR | Genius Media Group | Datatiedostot | Crossword Genius Data | FirstStop WebSearch | Open Source |
| .WUL | Open Source | Harvinaiset Tiedostot | WinUHA Language File | WinUHA | Open Source |
| .WV | David Bryant | Äänitiedostot | WavPack Audio File | XMMS | Open Source |
| .WVC | Open Source | Äänitiedostot | WavPack Correction File | WavPack | Open Source |
| .WVE | Wondershare Software Co., Ltd. | Videotiedostot | Wondershare Filmora Project File | SoX | Open Source |
| .WVL | Open Source | Rasterikuvatiedostot | Wavelet Image | DjVu Reader | Open Source |
| .WVM | Google | Videotiedostot | Google Play Video File | HandBrake | Open Source |
| .WX | Open Source | Varmuuskopiointitiedostot | Wanam Xposed Backup File | Wanam Xposed | Open Source |
| .WXM | Open Source | Harvinaiset Tiedostot | wxMaxima Batch File | wxMaxima | Open Source |
| .WXP | Open Source | Videotiedostot | Wax 2.0 Project | DebugMode Wax | Open Source |
| .WXR | Open Source | Datatiedostot | WxWindgets Resource Data | wxWidgets | Open Source |
| .WZ | Nexon | Pelitiedostot | MapleStory Game Data File | Warzone 2100 | Open Source |
/1 
