What is an MQ4 File?

How to Open and Convert This Type of File

Man looking at computer
What is an MQ4 File?. Thomas Barwick / Getty Images


What is an MQ4 File?

Did you find an MQ4 file on your computer and wonder what program should open it? Maybe someone emailed you an MQ4 file but you're not sure how to use it. Perhaps you tried to open the MQ4 file but Windows told you that it could not open it.

Before you can open an MQ4 file (assuming it's even a file format that's intended to be viewed or edited), you'll need to determine what kind of file the .MQ4 file extension refers to.


A file with the MQ4 file extension is a MacroMolecular Crystallographic Information file.

Other types of files may also use the MQ4 file extension. If you know of any additional file formats that use the .MQ4 extension, please let me know so I can update this information.

How To Open an MQ4 File:

The easiest way to open an MQ4 file is to double-click on it and let your PC decide which default application should open the file. If no program opens the MQ4 file then you probably don't have an application installed that can view and/or edit MQ4 files.

Warning: Take great care when opening executable file formats received via email or downloaded from websites you're not familiar with. See my List of Executable File Extensions for a listing of file extensions to avoid and why.

MQ4 files contain code written in the MetaQuotes language and can be opened with MetaQuotes MetaTrader.

If you know anything else useful about MQ4 files, please let me know so I can update this page.

Tip: Use Notepad or another text editor to open the MQ4 file. Many files are text-only files meaning no matter the file extension, a text editor may be able to properly display the file's contents. This may or may not be the case with MQ4 files but it's worth a try.

If you find that an application on your PC does try to open the MQ4 file but it's the wrong application or if you would rather have another installed program open MQ4 files, see my How To Change the Default Program for a Specific File Extension guide for making that change in Windows.

How To Convert an MQ4 File:

There are two main ways to attempt to convert an MQ4 file to another file type:

The first option involving opening the MQ4 file in its native program is preferable because it's both easier and will probably result in a more accurate file conversion. Of course, if you don't have a program that opens MQ4 files, a third-party file conversion tool (the second option) could be very useful.

Important: You cannot usually change a file extension (like the MQ4 file extension) to one that your computer recognizes and expect the newly renamed file to be usable. An actual file format conversion using one of the methods described above must take place in most cases.

Still Having Problems Opening or Using an MQ4 File?

See Get More Help for information about contacting me on social networks or via email, posting on tech support forums, and more. Let me know what kinds of problems you're having with opening or using the MQ4 file and I'll see what I can do to help.