How to open a .dll file (Windows, Mac, Linux)

Q: Why can't I open my .dll file?

Usually your computer lacks an app that understands DLL. Install one of the apps listed here, or convert the file to a more common format.

A .dll file is a Dynamic Link Library. If double-clicking does nothing, your computer simply does not have an app that reads DLL yet. Here is how to fix that on each operating system, using free software wherever possible.

Open a .dll file step by step

Confirm the file really is a .dll. Drop it into the WhatFileType file identifier, which reads its signature without uploading anything.
On Windows, open it with Loaded by programs, not opened directly or Dependency viewers for inspection.
On Mac, use Not applicable.
On Linux, try Not applicable (uses .so instead).
Still stuck? Convert the .dll to Not convertible, which opens more widely.

Best apps to open .dll files

Windows

Loaded by programs, not opened directly
Dependency viewers for inspection

macOS

Not applicable

Linux

Not applicable (uses .so instead)

Web

Not applicable

Before you open it: A DLL can contain executable code, so never drop unknown DLLs into program folders. Only replace a DLL with one from the official software vendor.

Frequently asked questions

Why can't I open my .dll file?

Almost always because no installed app understands DLL. Install one of the apps above, or convert the file to a format your existing software already reads.

A program says a DLL is missing. What do I do?

Reinstall or repair the program that needs it, or install the matching runtime (such as the Visual C++ Redistributable). Do not download loose DLLs from random sites.

Is it safe to download a DLL file?

No. Third-party DLL download sites are a well-known malware vector, and a mismatched version usually causes more errors than it fixes. Get the file only by reinstalling the software or installing its official runtime.