A: No. The official compiler is part of MetaEditor, which is installed with MT4. Avoid online “converters”—they are almost always scams.
The most immediate reason: MT4 only runs EX4 files. You cannot attach an MQ4 file to a chart or run it in the Strategy Tester. Compiling (converting) is a prerequisite for any backtesting or live trading. mq4 to ex4
Cause: You are using a variable that hasn’t been defined.
Fix: Declare the variable using int, double, string, or bool before using it. A: No
| Aspect | MQ4 (Source) | EX4 (Compiled) | |--------|--------------|----------------| | Speed | Interpreted on the fly | Native execution – faster | | Code Protection | Fully exposed | Hidden from users | | Distribution | Everyone can see/modify your logic | Safe for commercial sale | | Memory Footprint | Larger (source + compile each run) | Smaller, pre‑optimized | The most immediate reason: MT4 only runs EX4 files
For developers selling trading robots, compiling to EX4 is the standard way to protect intellectual property. The buyer can use the EA but cannot see or steal the proprietary logic.
When running a live EA, a single accidental edit to an MQ4 file could break the logic or cause trading errors. By using an EX4 file, you ensure the code remains unchanged during operation.