MT4 vs MT5
for Robots
The two platforms share a maker and nothing else that matters here. Language, tester and account mode each decide whether a tested robot stays tested.
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Key takeaways
- MT4 runs MQL4 and MT5 runs MQL5. A robot built for one will not run on the other.
- MT5 tests on real ticks and several symbols at once. MT4 models ticks from bars.
- A smoother MT5 backtest is not a better strategy. It is a more honest measurement.
- Hedging and netting differ. A grid robot behaves differently on a netting MT5 account.
- Check which platform the vendor actually tested on before you choose the account type.
Why Won't an MT4
Robot Run on MT5?
Two languages, two compiled formats, and no compatibility mode between them.
MT4 and MT5 look similar and share a maker. They run different programming languages.
A robot built for one will not load on the other. There is no compatibility mode.
This is the first thing to settle. Everything else follows from which version you actually hold.
Two languages, two files
- MT4 runs programs written in MQL4, compiled to an .ex4 file.
- MT5 runs MQL5, compiled to .ex5. The two formats are not interchangeable.
- Porting means rewriting the code, not copying the file across.
- A vendor selling both versions maintains two separate products.
What that means when buying
- Ask which version was tested. The other one may have no live record.
- A ported robot is a new product, whatever the version number says.
- Settings files do not transfer either, so the tuning restarts.
A published record from the MT4 version says nothing about the MT5 build. Ask for the record of the one you are buying.
How Do the Backtest
Engines Differ?
Modelled ticks against real ticks, and why a smoother curve is not a better one.
The strategy tester is where the two platforms differ most. MT5 measures more carefully.
This matters when reading a vendor backtest. The same strategy produces different curves on each tester.
The MT4 tester
- Models ticks from bar data, so the price path inside a bar is invented.
- Tests one symbol at a time, which hides correlation between positions.
- Reports a modelling quality figure that is often ignored.
The MT5 tester
- Uses real tick history where the broker supplies it.
- Tests several symbols together, so a portfolio can be measured.
- Models spread changes rather than assuming a fixed one.
A smoother MT5 curve is not a better strategy. It is a more honest measurement of the same rules.
The reverse trap is more common. An MT4 backtest on modelled ticks can look far better than reality.
Either way, a backtest remains a rehearsal. The distinction is drawn in backtest vs forward test.
Scalping systems are hit hardest by modelled ticks. Their whole edge sits inside a single bar.
What Hedging and
Netting Change
How the platform counts positions on one symbol, and what that does to a grid.
MT4 accounts are always hedging. MT5 accounts are either hedging or netting, and the broker decides.
The difference is how the platform counts positions on one symbol. It changes what a robot can do.
Hedging accounts
- Every order is a separate position with its own ticket.
- Buy and sell on the same symbol can be open at the same time.
- A grid keeps each level visible and closes them individually.
Netting accounts
- One symbol holds one position, and new orders adjust its size.
- An opposite order reduces or closes the existing position.
- A grid cannot hold its levels separately, so its logic changes.
A grid robot on a netting account behaves differently from the same robot on a hedging one.
Its levels merge into one position, so the recovery logic it was built around no longer applies.
Grid and martingale mechanics are set out in martingale and grid EAs.
Check the account mode before installing. A netting account can turn a tested grid robot into an untested one.
Frequently Asked Questions
Can I run an MT4 expert advisor on MT5?
No. MT4 runs MQL4 and MT5 runs MQL5, and the compiled files are not interchangeable. Porting means rewriting the code.
Is MT5 better than MT4 for robots?
Its tester measures more honestly, using real ticks and several symbols. That makes it a better measuring tool, not a better strategy.
What is the difference between hedging and netting?
A hedging account holds each order as its own position. A netting account keeps one position per symbol and adjusts its size.
Does a grid robot work on a netting account?
Not as designed. Its levels merge into one position, so the recovery logic it was built around no longer applies.
Which platform should I pick for an EA?
The one the robot was written and tested on. Check the published record, then check which platform it came from.
Continue Your Platform Cluster
Backtest vs Forward Test
What a tester can prove on either platform, and what only live money can.
Martingale and Grid EAs
The mechanics that behave differently the moment the account mode changes.
VPS for Forex Robots
Which terminal to install on the rented server, and what latency to accept.
Order Types & Stop Loss
How each order type behaves once it reaches the broker, on either platform.
Robot Rankings
Seven funded tests, each stating the platform and account mode used.