How to install an Expert Advisor in MT4 and MT5

An Expert Advisor — you will see it written as EA — is a program that runs inside MetaTrader and trades for you. Installing one takes five minutes and needs no programming. What is worth knowing are the two reasons almost everyone believes, the first time, that it does not work.

This guide applies to any Expert Advisor, whoever made it.

Before you start: which file you have

An Expert Advisor comes as an `.ex5` file (for MetaTrader 5) or an `.ex4` (for MetaTrader 4). That is the compiled, ready-to-use program.

Sometimes you are given an `.mq5` or .mq4: that is the source code and it has to be compiled first. If you are handed one of those and do not know what to do with it, ask for the compiled file — that is normal and what most providers deliver.

Step 1 · Open the right folder

This is where most people get lost, because the folder is not where you would expect.

1. Open MetaTrader.
2. Menu File → Open Data Folder.
3. A file window opens. Go into MQL5 → Experts (or MQL4 → Experts on MT4).

Leave that window open.

Step 2 · Copy the file and restart

Copy your .ex5 into the Experts folder. No subfolders needed.

Then close MetaTrader and open it again. If you do not restart, the new program will not appear in the list — and that is the first false alarm that catches a lot of people.

When it reopens, look at the Navigator panel (if you cannot see it: View → Navigator, or Ctrl+N). Under Expert Advisors yours should be there.

Step 3 · Drag it onto a chart

Open the chart of the pair you want and drag the advisor from the Navigator onto the chart. A settings window opens with two tabs that matter:

• Common: tick "Allow Algo Trading". Without this, the program installs but cannot open anything.
• Inputs: this is where the details your provider gave you go. Copy them exactly.

Press OK.

Step 4 · Switch on AutoTrading

On MetaTrader's top bar there is a button labelled AutoTrading (or Algo Trading in some versions). It has to be green. If it is red, the advisor is loaded and will never trade.

It is a global switch: it turns every advisor on or off at once. And it is, by a distance, the number-one reason for "the program does nothing".

The sad face, and what it actually means

In the top-right corner of the chart a small face appears next to the advisor's name:

• Smiley face 🙂 — active and able to trade. All correct.
• Sad face 🙁 — loaded but unable to trade.

The sad face does not mean the program is broken. It means one of three things, in this order of likelihood:

1. The AutoTrading button is red. Switch it on.
2. You did not tick "Allow Algo Trading" when you dragged it on. Right-click the chart → Expert List → Properties, and tick it.
3. You are on an investor (read-only) account instead of the trading account.

How to check it is alive

Do not trust the face: look at the Experts tab at the bottom, next to "Trade" and "History". That is where the advisor writes what it is doing. If it leaves a startup line when it launches, it is working.

If that tab is empty, it never started: go back over steps 2 and 3.

One important warning

While MetaTrader is closed, the advisor does not run. An Expert Advisor lives inside the platform: if you switch off the computer, it stops trading.

That is why many people leave MetaTrader open on the computer they already use, or on a VPS if they prefer not to depend on theirs. And it is why it is worth testing any advisor first on a demo account or in simulation mode, before it touches real money.

Common mistakes, as a list

• It does not appear in the Navigator → you did not restart MetaTrader after copying the file.
• Sad face → AutoTrading red, or the algo-trading permission is missing.
• It appears but opens nothing → check the Experts tab: it almost always tells you the exact reason.
• You copied the file into the wrong folder → it has to be MQL5/Experts, not MQL5/Scripts or MQL5/Indicators.
• You have an `.mq5` instead of an `.ex5` → ask your provider for the compiled file.

FAQ