| Extension |
File Type |
File Description |
| .q1q | Plugin | LunarCell Photoshop Plug-in |
| .q2q | Plugin | Flexify Photoshop Plug-in |
| .q4q | Plugin | Solar Cell Photoshop Plug-in |
| .q5r | Plugin | Melancholytron Photoshop Plug-in |
| .q7q | Plugin | India Ink Photoshop Plug-in |
| .q8r | Plugin | Flood Photoshop Plug-in |
| .q9r | Plugin | Glitterato Photoshop Plug-In |
| .q9s | Plugin | Mr. Contrast Photoshop Plug-In |
| .qbb | Backup | QuickBooks Backup File |
| .qbw | Data | QuickBooks Data File |
| .qbx | Backup | QuickBooks Accountant Transfer File |
| .qcp | Audio | PureVoice Audio File |
| .qda | Compressed | Quadruple D Archive |
| .qdf | Data | Quicken Data File (Most common) |
| .qdf | Data | Quicken Data File (Most common) |
| .qdfm | Data | Quicken Data File (Macintosh) |
| .qdl | Text | QDL Program |
| .qel | Data | Quicken Electronic Library |
| .qf | Web | Qompose Web Page Template (Most common) |
| .qfx | Data | Quicken Financial Exchange File |
| .qic | Backup | Windows Backup File |
| .qif | Data | Quicken Interchange Format File (Most common) |
| .qlgenerator | Plugin | Quick Look Generator File |
| .qpb | Data | Quicken Payroll File |
| .qph | Data | Quicken Price History File |
| .qpm | Data | Quick Pallet Maker Input Data |
| .qpr | Developer | FoxPro Generated Query Program |
| .qpw | Data | Quattro Pro Spreadsheet |
| .qpx | Plugin | QuickTime Player Extension (Most common) |
| .qpx | Plugin | QuickTime Player Extension (Most common) |
| .qrm | Web | Qworum Message File |
| .qsf | Backup | Qualtrics Survey File |
| .qt | Video | Apple QuickTime Movie |
| .qtch | Video | QuickTime Cache File |
| .qti | Image | QuickTime Image File |
| .qtif | Image | QuickTime Image File |
| .qtl | Video | QuickTime Link File |
| .qtr | Plugin | QuickTime Extension Resource |
| .qtx | Plugin | QuickTime Extension |
| .qtz | Video | Quartz Composer File |
| .qwd | Game | QuakeWorld Demo File |
| .qx | Developer | Quexal Source Code |
| .qxd | Page Layout | QuarkXPress Document |
| .qxl | Misc | QuarkXPress Library |
| .qxp | Page Layout | QuarkXPress Project File |
| .qxt | Page Layout | QuarkXPress Template |
