What Is an EX4 File?
A file with the EX4file extensionis a MetaTrader 4 program file.
It’s compiled programming code made for the free foreign exchange market trading program called MetaTrader.

Stored in one of these files may be scripts or indicators used by that software.
The file could instead be an Expert Advisor (EA) program used by MetaTrader for automating trading.
How to Open an EX4 File
EX4 files can be opened with the free MetaTrader program fromMetaQuotes.
It works on Windows, macOS, and Linux.
You have to know what the EX4 file is, specifically, so you know where to put it.
In MetaTrader, you could see these files in the “Navigator” window.
If you don’t see that window, enable it viaView>Navigator.
We’re not aware of any decompilers that can do this.
You might be able to convert EX4 to EX5 or AFL (AmiBroker Formula Language).
Still Can’t Open It?
If you could’t open your file with MetaTrader, it’s most likely not in a compatible format.
This might happen if you’ve misread the file extension, which is surprisingly easy to do.
Trying to open those files in MetaTrader will most likely result in an error.
X4K is another example, but the file extension is reserved for XML4King configuration files.
Those files won’t work in MetaTrader, and neither will EX4 files open in XML4King.
Ext4 is afile systemthat has nothing at all to do with EX4 files.