Since MetaQuotes introduced strong encryption and anti-decompilation measures in MT4 build 600 (2014) and later builds (1080, 1355, etc.), online converters have become virtually obsolete for protected code.
Finding a reliable, free online tool for this conversion is challenging. The technology has evolved significantly. This updated guide covers everything you need to know about converting EX4 to MQ4 online safely. Understanding EX4 vs. MQ4 Files convert ex4 to mq4 online free updated
Do not upload proprietary EX4 files to unverified "free online converter" websites. convert ex4 to mq4 online free updated