If the EA is trivial (moving average cross + stop loss), rewriting from scratch in MQL4/MQL5 takes 1–2 hours. You will end up with cleaner, documented, maintainable code.
The worst-case scenario for safety, but best for your PC: the EXE just shows a fake progress bar, then outputs a generic “error” or an MQ4 file filled with InvalidFunction and comment lines like “Decompiled with demo version – buy full version for $299.” This is just a upsell scam. ex4 to mq4 decompiler50 1 exe top
If you manage to find a file with that exact name (or any similar free decompiler), what are you actually downloading? In 99% of cases, one of the following: If the EA is trivial (moving average cross
| File Type | Description | |-----------|-------------| | MQ4 | Source code (human-readable) | | EX4 | Compiled binary (bytecode for MetaTrader 4 virtual machine) | | Decompiler | Attempts to reverse EX4 → approximate MQ4 | ex4 to mq4 decompiler50 1 exe top
Since MetaQuotes introduced strong encryption around 2014–2016, modern EX4 files cannot be reliably decompiled to readable source code. Most claimed tools are scams.