What is the MFX file format?
.mfx files are plugin extensions for Clickteam Fusion 2.5 (formerly Multimedia Fusion 2), a Windows-based game and application development tool. Each .mfx file is a standard Windows DLL (Dynamic Link Library) renamed with a .mfx extension - it begins with the standard MZ PE (Portable Executable) header at offset 0.
An .mfx extension adds a new object type to the Clickteam Fusion IDE. It exports a defined set of Clickteam extension API functions that register the object's actions, conditions, expressions, and properties with the editor. Once placed in the Extensions\ subfolder of the Clickteam Fusion installation directory, the object becomes available in the Create new object dialog.
The .mfx format replaced the older .COX extension format used in The Games Factory 1 and earlier Clickteam products. Both official Clickteam extensions and a large catalog of third-party community extensions are distributed as .mfx files, accessible through the Clickteam Extension Manager.
Because .mfx files are 32-bit Windows DLLs, they function only within Clickteam Fusion on Windows and cannot be executed as standalone programs. Extensions allow Clickteam Fusion to interface with hardware devices, networking, physics engines, and other platform capabilities beyond the built-in feature set.
Security & safety
RISK: MEDIUMMFX files are Windows DLLs and can contain arbitrary executable code. Only install .mfx extensions from trusted sources (Clickteam official, well-known community contributors). Malicious MFX files could theoretically be used as a vector when loaded by Fusion. Do not install MFX files from unknown sources.
Format details
in a nutshell- Adobe keyboard shortcut file - Some Adobe applications reportedly use .mfx for user keyboard shortcut configuration files; unrelated to Clickteam.
Programs that open MFX files
Windows3 apps
Clickteam Fusion 2.5
Freemium Copy .mfx to the Extensions\ folder inside Clickteam Fusion 2.5's install directory, or use the built-in Extension Manager. The extension then appears in 'Create new object'.
Multimedia Fusion 2
Paid Copy .mfx to the Extensions\ folder; MFX files from Multimedia Fusion 2 era are also compatible with Clickteam Fusion 2.5.
The Games Factory 2
Paid Copy .mfx to the Extensions\ folder. Legacy product; Clickteam Fusion 2.5 is the current successor. Technical details
deep spec| File signature | MZ (0x4D 0x5A) at offset 0 - standard Windows PE/DLL header |
| Encoding | Binary |
| Byte order | Little-endian (x86 Windows DLL) |
| Container | Windows PE DLL (Portable Executable dynamic-link library) with .mfx extension |
| Architecture | 32-bit x86 Windows DLL |
| API | Exports Clickteam Fusion extension SDK functions defining the object's actions, conditions, expressions, and properties |
| Install location | Extensions\ subfolder of the Clickteam Fusion installation directory |
| Typical file size | 50 KB - 5 MB |
| Compression | None at DLL level; embedded resources may use internal compression |
| Execution | Loaded only within Clickteam Fusion 2 / Multimedia Fusion 2 or Fusion 2.5; not a standalone executable |
| Predecessor format | .COX (The Games Factory 1 and earlier Clickteam products) |
| Distribution | Clickteam Extension Manager; community repositories and ClickStore |
| Released | 2001 (Multimedia Fusion 2 / The Games Factory 2 era) |
| Latest version | Clickteam Fusion 2.5+ compatible MFX (current) |
| Specification | clickwiki.github.io |
MFX conversions
Community Q&A
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