| x3f | Sigma RAW Image |
| xar | Xara Drawing |
| xb | XBin Image |
| xbm | X Bitmap Image |
| xcf | Gimp Image |
| xcfbz2 | Gimp BZip2 Compressed XCF |
| xface | X-Face Image |
| xfx | OAZ Fax Image |
| xga | Atari Falcon XGA Image |
| xif | Pagis Pro Scanned Image |
| xifs | PixInsight XIFS Data |
| xim | XImage Bitmap |
| ximg | Atari ST Extended GEM Bit Image |
| ximg | IDV Image XML |
| xisf | PixInsight XISF Data |
| xjt | Gimp Jpeg-Tar File |
| xlp | Atari 8-bit XL-Paint Image |
| xmp | Adobe XMP Metadata |
| xos | Xaos Tools Bitmap Image |
| xpif | Extended Processed Image File |
| xpm | X Pixmap |
| xqd | Seiko Microscope Image |
| xqf | Seiko Microscope Image |
| xsp | XBMC Smart Playlist |
| xtf | eXtended Triton Format File |
| xtx | Xbox 360 XTX Texture Data |
| xv | Khoros Visualization Image |
| xvc | MuPAD Uncompressed VCam Graphic |
| xvz | MuPAD Compressed VCam Graphic |
| xwd | X Window Dump |
