| Extension | Description | File Type |
|---|
| h | C/C++ Header File | Developer Files |
| h264 | H.264 video file | Video Files |
| h2w | H2testw File | Executable Files |
| hdp | HD Photo File | Graphic Files |
| hdr | High Dynamic Range Image File | Graphic Files |
| hdr | InstallShield Setup Header | Misc Files |
| hds | Windows Digital Right Management File | Encrypted Files |
| hds | Hierarchical Dataset File | Geographical Files |
| hex | Hexadecimal Source File | Misc Files |
| hfs | Macintosh Disc Image File | Disk Image Files |
| hlp | Microsoft Help File | System Files |
| hmt | HighMat File | Disk Image Files |
| hpp | C++ Header File | Developer Files |
| hqx | Macintosh BinHex Encoded File | Encoded Files |
| hst | Yahoo Messenger History File | Misc Files |
| hta | HTML Application | Executable Files |
| htaccess | Access Configuration File | Settings Files |
| htc | HTML Component File | Web Files |
| htm | Hypertext Markup File | Web Files |
| html | HTML 1.0 | Web Files |
| htt | Hypertext Template File | Settings Files |
| hus | Husqvarna Embroidery Machines File | Misc Files |
| hwp | Hangul Document File | Text Files |