Converting Pine Script to MQL5: A Comprehensive Guide

So you've got this awesome trading strategy working perfectly on TradingView, but now you want to run it on MetaTrader 5? Yeah, I've been there. Converting Pine Script to MQL5 isn't exactly a walk in the park, but it's totally doable once you know what you're dealing with.

What You're Getting Into

First things first - Pine Script and MQL5 are like two different languages that happen to talk about the same stuff. Pine Script is TradingView's thing, and it's honestly pretty straightforward. MQL5? Well, it's what MetaTrader 5 uses, and it's... let's just say it's a bit more old-school.

The tricky part isn't just translating words from one language to another. It's making sure your strategy still does exactly what it's supposed to do after you move it over. Trust me, you don't want to find out your converted strategy is doing something completely different when real money is on the line.

The Main Differences (And Why They Matter)

Here's what you need to wrap your head around:

Pine Script is like texting - short, sweet, gets to the point. MQL5 is more like writing a formal letter - you need to be way more explicit about everything.

Function names are different - What Pine Script calls sma(), MQL5 calls something completely different. It's like learning that "elevator" and "lift" mean the same thing.

Variables need labels - In Pine Script, you can just say price = close and it figures out what you mean. MQL5 wants you to spell out exactly what type of variable you're creating.

Drawing stuff works differently - How you show lines, colors, and indicators on the chart? Totally different approach.

Making Sense of Your Pine Script First

Before you start converting anything, you really need to understand what your Pine Script is actually doing. I mean really understand it.

This is where visual tools like Pineify can actually save you a ton of headache. Instead of staring at code trying to figure out what's happening, you can see the logic laid out visually. It's like having a map instead of just street names - way easier to navigate.

Website: Pineify

Check out what Pineify can do.

How I Usually Do The Conversion

Step 1: Break Down Your Pine Script

Don't just jump into converting. Sit down with your Pine Script and make a list:

• What inputs does it need?
• What calculations is it doing?
• When does it buy or sell?
• What does it show on the chart?

Seriously, write this stuff down. You'll thank me later.

Step 2: Find the MQL5 Equivalents

This is where you become a translator. You need to figure out how to say the same thing in MQL5. For example:

• Pine Script's sma(close, 20) becomes iMA(NULL, 0, 20, 0, MODE_SMA, PRICE_CLOSE, 0) in MQL5
• Pine Script's ema(close, 20) becomes iMA(NULL, 0, 20, 0, MODE_EMA, PRICE_CLOSE, 0) in MQL5

Yeah, MQL5 is way more verbose. Get used to it.

Step 3: Set Up Your MQL5 Structure

MQL5 has this whole structure you need to follow. Think of it like filling out a form - there are specific sections that need to be filled out:

#include <Trade\Trade.mqh>

// Your settings go here
input int MyLength = 14;

// Variables you'll use
double MyArray[];

// This runs once when you start
int OnInit()
{
   // Setup stuff
   return(INIT_SUCCEEDED);
}

// This runs every time there's a new price tick
void OnTick()
{
   // Your main logic goes here
}

Step 4: Actually Convert the Logic

Now comes the fun part (and by fun, I mean potentially hair-pulling). You need to take each piece of your Pine Script logic and recreate it in MQL5.

The key is to go slow and test each piece as you build it. Don't try to convert everything at once - you'll just end up with a mess that doesn't work and you won't know why.

Step 5: Test Everything

I cannot stress this enough - test your converted code like your life depends on it. Run it on demo accounts, compare the results with your original Pine Script, and make sure it's doing what you expect.

The Stuff That Usually Trips People Up

Custom Functions: If your Pine Script uses some fancy custom functions, you'll need to recreate those in MQL5. Sometimes it's easier to just write them from scratch.

How Things Happen: Pine Script runs through your code from top to bottom every time. MQL5 is more event-driven - it waits for things to happen and then responds. It's a different way of thinking.

Memory Management: MQL5 makes you think about memory more. You need to properly set up your arrays and variables, or things can get weird fast.

Tools That Actually Help

Look, there are some AI tools out there that claim they can automatically convert Pine Script to MQL5. Some are better than others, but don't expect miracles. They're good for getting started, but you'll probably need to fix a bunch of stuff manually.

The MQL5 documentation is actually pretty good once you get used to it. And the forums are full of people who've been through the same struggles you're going through.

A Real Example

Let me show you what a simple moving average crossover looks like in both languages:

Pine Script version:

//@version=4
strategy("Simple MA Crossover")
fast_length = input(9, title="Fast Length")
slow_length = input(21, title="Slow Length")
fast_ma = sma(close, fast_length)
slow_ma = sma(close, slow_length)

if (crossover(fast_ma, slow_ma))
    strategy.entry("Buy", strategy.long)
if (crossunder(fast_ma, slow_ma))
    strategy.entry("Sell", strategy.short)

plot(fast_ma, color=color.blue)
plot(slow_ma, color=color.red)

MQL5 version:

#include <Trade\Trade.mqh>

input int FastLength = 9;
input int SlowLength = 21;

CTrade trade;
double FastMA[], SlowMA[];

int OnInit()
{
   ArraySetAsSeries(FastMA, true);
   ArraySetAsSeries(SlowMA, true);
   return(INIT_SUCCEEDED);
}

void OnTick()
{
   // Get the moving averages
   int copied1 = CopyBuffer(iMA(_Symbol, _Period, FastLength, 0, MODE_SMA, PRICE_CLOSE), 0, 0, 3, FastMA);
   int copied2 = CopyBuffer(iMA(_Symbol, _Period, SlowLength, 0, MODE_SMA, PRICE_CLOSE), 0, 0, 3, SlowMA);
   
   if(copied1 <= 0 || copied2 <= 0) return;
   
   // Check if fast MA crossed above slow MA
   if(FastMA[1] <= SlowMA[1] && FastMA[0] > SlowMA[0])
   {
      trade.Buy(0.1);
   }
   
   // Check if fast MA crossed below slow MA
   if(FastMA[1] >= SlowMA[1] && FastMA[0] < SlowMA[0])
   {
      trade.Sell(0.1);
   }
}

See the difference? The MQL5 version is way more verbose, but it's doing the same thing.

Wrapping Up

Converting Pine Script to MQL5 is definitely doable, but it's not a five-minute job. Take your time, understand what you're working with, and don't be afraid to ask for help when you get stuck.

If you've got a really complex strategy and you're not comfortable with the conversion process, it might be worth finding someone who knows both languages well. Sometimes it's better to pay someone to do it right than to spend weeks fighting with code that doesn't work.

The main thing is to make sure your converted strategy actually works the way you expect it to. All the time you spend converting is worthless if the end result doesn't trade properly.