DLL file is an executable file which is used as "Dynamic Link Library" or "Application Extension". Microsoft Windows applications can open DLL file and execute code from it. One DLL file could be shared between multiple Windows application. Also Microsoft Windows OS uses DLL files to store executable code for different windows components (graphical engine, networking, printing, etc.).
DLL is one of the most frequently occuring file extensions on your PC. Most of DLL files are located in C:\Windows\System32 folder. Also Windows applications store DLL files in their corresponding folders in "Program Files" and "Program Files (x86)" folders. When you launch a Windows OS application it will look for its DLL files in the folder where you launch it from and will try to open DLL files and load them into memory.
Mac OS uses different format for application library files and thus it is not possible to open DLL files on Mac OS operating system.
If you want to check if a specific file is a DLL you can do it via following methods:
Below is an example of DLL file opened in Dependency Walker in Windows OS.
Please note that DLL files could contain dangerous viruses that can do serious damage to your computer. Do not download DLL files from the internet and do not replace your local DLL files with ones which origin is questionable.
Applications which can open DLL files
Similar file extensions
| Extension Details |
|---|
Dynamic Link Library |
| MIME Type |
application/x-msdownload application/octet-stream application/x-msdos-program |
| Identifying Characters |
![]() Hex: 4D 5A |
| Opens with |
Text Editor Microsoft Visual Studio Microsoft Disassembler |