MDL File

What are MDL files and how to open them

Are you having problems opening a MDL file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your MDL files.

What is a MDL file?

MDL files have multiple uses, and Half-Life 3D Model is one of them. Read more about the other uses further down the page.

Half-Life 3D Model

Half-Life is a series of first-person shooter games developed by Valve. The MDL files used by these games contain 3D models, including meshes, objects, and textures. MDL files are often used to create buildings and objects within gaming applications. Popular applications that use the .mdl file extension include Warcraft III, Half-Life, and Quake.

How to open MDL files

We have identified one MDL opener that is compatible with this specific type of MDL file.

Programs that open Half-Life 3D Model files

Last updated: August 9, 2026

All known file formats using extension .MDL

While Half-Life 3D Model is a popular type of MDL-file, we know of 13 different uses of the .MDL file extension. Different software may use files with the same extension for different types of data.

3-D Helicopter Simulator Model

We know that one MDL format is 3-D Helicopter Simulator Model. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

While we have not verified the apps ourselves yet, our users have suggested ten different MDL openers which you will find listed below.

CA-Compete! Model

We know that one MDL format is CA-Compete! Model. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

CAB Module

We know that one MDL format is CAB Module. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Digitrakker Music Module

We know that one MDL format is Digitrakker Music Module. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Javelin Model

We know that one MDL format is Javelin Model. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

KeyCAD Deluxe 3D Model

We know that one MDL format is KeyCAD Deluxe 3D Model. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Luigi's Mansion 3D Model

We know that one MDL format is Luigi's Mansion 3D Model. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

MDL 3D Game Studio Model

We know that one MDL format is MDL 3D Game Studio Model. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Microsoft Flight Simulator 3D Model

Microsoft Flight Simulator 3D Model (.MDL) is a proprietary file format used by Microsoft Flight Simulator to store 3D visual representations of aircraft, scenery, and other in-game objects. Files in this format are created when a model is built for the simulator - either by official content or add-on developers - and they hold geometry and drawing information, references to external textures, and, in newer versions, support for animated parts like flaps, landing gear, or propellers.

These .MDL files are read by flight simulator software so the virtual world can display objects, planes, or scenery correctly on screen. Depending on version, the format differs: older simulators (like FS95/FS98) use an older custom binary stream of draw commands and vertex data; from Flight Simulator 2002 onward Microsoft moved to a RIFF-chunked structure with variants called MDL8 (used for aircraft), MDL9 (used for scenery and some aircraft), and MDLX (used in FSX) to support features like animated model components. Third-party tools often convert MDL files to more common 3D formats (like OBJ, DXF) to allow editing in standard programs.

Within the RIFF-based versions, the file begins with the ASCII signature "RIFF" at offset 0, followed at offset 8 by "MDL" and then at offset 12 by "MDLH," which helps programmatic tools identify that this is a Microsoft Flight Simulator MDL model.

MDL opener for Windows

We have identified one MDL opener that is compatible with this specific type of MDL file.

Mighty Draw DOS Library

We know that one MDL format is Mighty Draw DOS Library. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

MoRay 3D Model

The MoRay 3D Model file is used by Moray, a wireframe modeling and scene-layout tool for creating 3D visuals that are exported to POV-Ray. Moray lets you build scenes interactively using wireframes, assign textures, and arrange geometry, then save content in its native format with extension .MDL before rendering or exporting.

Files with this .MDL format are written by Moray. Typical use is building or editing a scene - including objects, camera, lights, textures - in Moray; then either rendering directly in Moray or exporting to a POV (.pov) scene file (and accompanying .inc, .ini files) for more advanced editing or final rendering.

Internally, Moray's .MDL starts with the ASCII signature "MDL" at byte offsets 0-2. That signature identifies the file as Moray's 3D model format.

Programs that open these MDL files

We have identified one MDL opener that is compatible with this specific type of MDL file.

Simulink Library

We know that one MDL format is Simulink Library. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Various apps that use files with this extension

These apps are known to open certain types of MDL files. Remember, different programs may use MDL files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about MDL file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.