| h5 | Hierarchical Data Format Release 5 |
| h5b | Line 6 POD HD500 Edit Bundle |
| h5e | Line 6 POD HD500 Edit Preset Data |
| h5s | Line 6 POD HD500 Edit Setlist Data |
| h6h | JUKI HLC Script |
| h6x | Soft6502 Trainer/Simulator Hex Data |
| h77t | GEODAS MGD77T Header Data |
| h86 | CP/M Data |
| haas | Everfine HAAS Test Results Data |
| had | Haydee Web Server Module Style |
| hal | HotDocs Answer Library |
| halog | IEInspector HTTP Analyzer Log |
| hamachi | Hamachi Client Data |
| har | HTTP Archive |
| har | E-Sword Harmony Resource |
| harx | E-Sword v9.1 Harmony Resource |
| hash | EnCase Forensics Hash File |
| hashdb | HashDB Database |
| hat | HOORA Analysis Tool Model Data |
| hb | Harwell Boeing Sparse Matrix |
| hb2 | HBPLUS Output Data |
| hbb | Line 6 POD HD Edit Bundle |
| hbc | Homebanking Computer Interface |
| hbci | Homebanking Computer Interface |
| hbd | HardlinkBackup Backup Definition |
| hbin | HITRAN Binary Output |
| hbk | Hex Workshop Bookmark File |
| hbk | HandyCafe Data |
| hbn | Java Hibernate Data |
| hbp | HBPredicT Output |