A: Very old EX4 files compiled with MT4 build 509 or earlier (before obfuscation was added) might be partially decompilable. However, these builds are obsolete, and such files are rare.
Even with the best available tools, it's important to have realistic expectations about the decompilation outcome:
Older versions of MT4 compiled MQL4 code into a format very similar to standard PE (Portable Executable) files. Because the structure was simple and well-documented,
Still a violation in most jurisdictions unless the work is considered abandoned. "Abandonware" is rarely recognized in software copyright law.
Before attempting to reverse-engineer a trading file, consider the legal ramifications:
Before looking at third-party tools, ensure you do not already have access to the source code. MetaTrader 4 automatically backs up files in its directory structures. Check your platform's MQL4/Experts or MQL4/Indicators folders for a corresponding .mq4 file. If you are the original developer, check your code editor's local history. 2. Using EX4 Decompilers (Automated Software)
Search your computer's recycle bin, old email attachments, or cloud storage for the original .mq4 file.
In short, The Technical Reality: Can You Convert EX4 to MQL4?
Invest time in learning the MQL4 language. Understanding the syntax and logic allows you to create custom trading algorithms tailored precisely to your strategy. The official documentation and MQL5 community forums offer extensive resources for learning. This not only solves the immediate issue but is a valuable skill for any serious trader.
The code within an EX4 file is the intellectual property of the developer. Decompiling proprietary software without authorization is generally considered a violation of copyright law and software license agreements (EULA). Most EULAs explicitly prohibit reverse engineering.
Another option is to use online decompilation services. These websites offer to convert an EX4 file to MQL4 for you. The process usually involves uploading the EX4 file to their server, which then attempts the decompilation and provides a downloadable MQL4 file.
"Converting" is actually . Before 2014 (MetaTrader Build 600), decompiling was relatively simple because the file structure was basic.
