MetaQuotes (the developer of MetaTrader) explicitly forbids decompilation in their Freelance Service rules and considers it illegal in many jurisdictions.

: Decompiling someone else's code often violates intellectual property rights and MetaQuotes' terms of service. 🛠️ Legitimate Alternatives to Conversion

Directly converting an back to its original MQL4 (MQ4) source code is practically impossible for modern MetaTrader 4 (MT4) builds . While older versions (build 509 and lower) could be easily decompiled, files compiled after build 600 use advanced optimization and encryption that strip away human-readable elements like comments and variable names. Understanding the EX4 vs. MQL4 Difference

If you have been trading on the MetaTrader 4 (MT4) platform for any length of time, you have likely encountered two specific file extensions: and MQL4 .

: Hiring a specialized programmer via platforms like Insolvo or community forums like Forex Factory is often more effective for complex files . 3. Manual Reconstruction (The "Clean" Way)