Before proceeding, understand:
Proceed only if you own the rights to the code or have explicit permission from the author.
In 2023, a cybersecurity scan of 50 “free EX4 decompilers” showed:
If you have spent any time in the world of MetaTrader 4 (MT4), you have likely encountered this frustrating scenario: you have an amazing Expert Advisor (EA) or indicator, but it’s locked. It has an .ex4 extension. You want to edit the code, fix a bug, or understand how it works, but all you have is the compiled file.
A quick Google search for "how to convert ex4 to mq4 free work" returns thousands of links promising magical solutions, shady software, and "100% working decompilers." how to convert ex4 to mq4 free work
But do any of them actually work? And if they do, should you use them?
This article provides a complete, honest, and practical guide. We will cover:
If you compiled the EX4 yourself but lost the MQ4, and you did not check "Disable decompilation" in MetaEditor settings:
Steps:
Note: This only works on very old builds (before build 600) or unprotected files.
Many traders ignore this part, but it is critical.
Bottom line: If you bought an EA and want to modify it, ask the developer for the source code (pay an extra fee). If they refuse, respect that. Do not steal.
For the sake of completeness, let us discuss the actual process of decompiling an EX4 to MQ4—not because it is recommended, but so you understand why “free” tools fail. Before proceeding, understand:
Many decompilers are flagged as "hack tools" – disable AV only during the conversion, then re-enable.
Short answer: No, you cannot get the original MQ4 with variable names, comments, and structure exactly as the author wrote it.
Long answer: Yes, you can generate a working, recompilable MQ4 file from an EX4 using decompilation tools. The result will be:
So, free conversion gives you editable, but messy code.