| .T04 | Tobias Svensson | Pliki z obrazami 3D | Top 4 Compressed Data File | top 4 | Unknown Developer |
| .T3D | Epic Games | Pliki z obrazami 3D | Unreal Engine 3D Object File | Unreal Tournament | Epic Games |
| .TDDD | Impulse | Pliki z obrazami 3D | Imagine Object File Format | Impulse Imagine | Impulse |
| .TDIM | Unknown Developer | Pliki z obrazami 3D | Digital F/X Image Format | XnView MP | XnSoft |
| .TER | Planetside Software | Pliki z obrazami 3D | Terragen Terrain File | Planetside Software Terragen | Planetside Software |
| .TGM | Open Source | Pliki z obrazami 3D | Nem's Mega 3D Terrain Generator | Nem's Mega 3D Terrain Generator | Open Source |
| .THL | Individual Software Inc. | Pliki z obrazami 3D | Total 3D Home Design File | Total 3D Home Design Deluxe | Individual Software Inc. |
| .THUMBDATA3 | Google | Pliki z obrazami 3D | Google Android Thumbnail Database | Google Android | Google |
| .THUMBDATA5 | Google | Pliki z obrazami 3D | Google Android Thumbnail Database | Google Android | Google |
| .TIN | Bentley Systems | Pliki z obrazami 3D | Bentley GEOPAK Environmental Modeling Systems Data | GEOPAK Civil Engineering Suite | Bentley Systems |
| .TMD | SoftMaker Software | Pliki z obrazami 3D | TextMaker Document | Softmaker Office | SoftMaker Software |
| .TME | DAZ 3D | Pliki z obrazami 3D | Bryce Time File | DAZ 3D Bryce | DAZ 3D |
| .TML | Odetics Broadcast | Pliki z obrazami 3D | AIRO Timeline File Format | AIRO | Odetics Broadcast |
| .TMO | Yu Higuchi | Pliki z obrazami 3D | 3DCG Animation And Pose File | MikuMikuDance | Yu Higuchi |
| .TMP | Mozilla | Pliki z obrazami 3D | General Temporary File | Internet Explorer | Microsoft Corporation |
| .TNL | Unknown Developer | Pliki z obrazami 3D | Thumbnail Image Format | Unknown Software | Unknown Developer |
| .TOP | KTH Royal Institute of Technology | Pliki z obrazami 3D | Gromacs Topology File | Gromacs | KTH Royal Institute of Technology |
| .TOTAL COMMANDER BUTTON BAR SETTINGS | Interscape | Pliki z obrazami 3D | Total Commander Button Bar Settings | Total Commander | Ghisler Software GmbH |
| .TPS | TiePie engineering | Pliki z obrazami 3D | Multi Channel Measurement File | Multi Channel | TiePie engineering |
| .TRI | Singular Inversions | Pliki z obrazami 3D | FaceGen Polygonal Model File | The Elder Scrolls IV: Oblivion | Bethesda Softworks |
| .TRU | Original Basic | Pliki z obrazami 3D | True Basic Source | True Basic Bronze Edition | Original Basic |
| .TSO | Siemens AG | Pliki z obrazami 3D | NX2 File 3D Faceted Spacial Volume Data | Siemens PLM NX | Siemens PLM Software |
| .TVP | NVIDIA | Pliki z obrazami 3D | NVIDIA Graphic Card Update File | NVIDIA Graphics Driver | NVIDIA |
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