When you buy an Expert Advisor, you are usually offered one of two things: a compiled robot you can run, or the full source code you can read and edit. They are very different products at very different prices. Here is what buying source code actually gives you, and when it is worth it.
Compiled EA vs source code
- Compiled EA (
.ex5or.ex4): you can run it on a chart, but you cannot read the logic or change how it works. It is a sealed box. - Source code (
.mq5or.mq4): you get the actual human readable code. You can study it, modify it, compile it yourself, and in many cases rebrand it.
What is in a source code package
A proper source purchase should include:
- The complete
.mq5or.mq4file, not a stripped down demo. - Any include files (
.mqh) required to compile it. - A license note explaining what you are allowed to do, personal use, modification, resale, and so on.
- Often a manual describing the inputs and strategy.
Why source code costs more
With a compiled EA, the seller keeps their logic secret and can sell the same file many times. With source code, they are handing you their intellectual property. You can see every rule, copy the ideas, and build on them. That is worth more, so it usually costs more.
When source code is worth it
- You want to learn: reading real, working EAs is one of the best ways to learn MQL.
- You want to customize: change the strategy, add filters, adapt it to your broker or symbol.
- You want to build a product: with the right license, you can rebrand and resell it. See our reselling guide.
- You want transparency: with source you can verify exactly what the robot does before risking money on it.
When a compiled EA is enough
If you just want to run a strategy and never plan to change it, a compiled EA is cheaper and simpler. You do not need source to trade, only to read and modify.
Check the license every time
Buying source does not automatically mean you can resell it. Some source is sold for personal use and modification only. Always read the license note. Our guide on choosing safe source code covers what to look for.
Try before you buy
The best way to understand the value of source code is to work with some. Our free source library lets you download full, editable EAs at no cost so you can see exactly what a source package looks like. When you are ready for more advanced strategies, our premium catalog ships the same clean, documented source.