Code migration guide
MQL4 to Pine Script converter
MQL4 indicator buffers can often become Pine series and plots, but an Expert Advisor must be reduced to TradingView strategy simulation or alerts because ticket management and terminal callbacks are not available in Pine.
Generate a Pine Script draft, then validate it in TradingView Pine Editor and on the intended chart.
Conversion map
What changes between MetaTrader 4 and TradingView
The migration is a model translation. Use this map to decide where the source behavior belongs before writing target syntax.
| Concern | Source model | Target model | Migration decision |
|---|---|---|---|
| Lifecycle | Expert Advisors and indicators respond to predefined callbacks such as OnInit, OnTick, and OnCalculate. | Code runs sequentially across chart bars. Realtime behavior depends on script type and calculation settings. | Choose when each MetaTrader 4 calculation should run in TradingView; matching syntax alone does not preserve timing. |
| Market data and history | Price series use terminal arrays and shift-based access; indicators commonly expose calculated values through buffers. | Built-in series values such as close carry bar history and use history references such as close[1]. | Recheck bar indexing, warm-up requirements, timeframe requests, and behavior on an unfinished bar. |
| Indicators and chart output | Custom indicators bind buffers, while built-in indicator functions can return values directly for a requested shift. | indicator(), plot(), drawing objects, alerts, and the ta.* namespace define chart output. | Map calculations before recreating plots, labels, colors, and platform-specific drawing objects. |
| Orders and positions | Classic trade functions such as OrderSend work with order tickets, lots, prices, stops, and a shared order pool. | strategy.* commands create broker-emulator orders for TradingView strategy tests. | Define fill timing, sizing, pyramiding or hedging, stops, and position ownership for the target platform. |
| Native validation | Compile the .mq4 file in MetaEditor, attach it in MetaTrader 4, and test the correct EA or indicator artifact. | Save in Pine Editor, resolve compiler errors, add to a chart, then inspect plots, alerts, and Strategy Tester behavior. | Treat generated Pine Script as a draft until it passes the target editor, chart, and backtest workflow. |
Code example
Moving-average cross: MQL4 to Pine Script
These fragments show where the same signal starts in each API. They are not complete standalone programs; lifecycle setup, inputs, plots, and order handling still depend on the selected artifact.
double fast0 = iMA(NULL, 0, 10, 0, MODE_SMA, PRICE_CLOSE, 0);
double fast1 = iMA(NULL, 0, 10, 0, MODE_SMA, PRICE_CLOSE, 1);
double slow0 = iMA(NULL, 0, 20, 0, MODE_SMA, PRICE_CLOSE, 0);
double slow1 = iMA(NULL, 0, 20, 0, MODE_SMA, PRICE_CLOSE, 1);
bool longSignal = fast1 <= slow1 && fast0 > slow0;//@version=6
indicator("MA cross", overlay = true)
fast = ta.sma(close, 10)
slow = ta.sma(close, 20)
longSignal = ta.crossover(fast, slow)
plot(fast)
plot(slow)Workflow
A four-step migration path
Keep generation, target-platform validation, and behavior comparison as separate stages.
- 1
Inventory the source behavior
Separate calculations, plots, alerts, orders, external dependencies, and assumptions in an .mq4 Expert Advisor or custom indicator.
- 2
Choose the target artifact
Decide whether the result is a Pine Editor indicator or strategy source file. This choice controls lifecycle methods and available APIs.
- 3
Rewrite through target APIs
Translate state, series, indicators, drawings, and orders into TradingView concepts instead of replacing function names.
- 4
Validate behavior natively
Save in Pine Editor, resolve compiler errors, add to a chart, then inspect plots, alerts, and Strategy Tester behavior.
Manual decisions
Decisions code replacement cannot make
- Choose Pine indicator, strategy, or alert logic based on the portable part of the MQL4 program.
- Translate buffer shifts and ArraySetAsSeries assumptions into Pine history references.
- Replace OrderSend, ticket loops, and terminal state with Pine simulation or an external execution handoff.
Limitations
What the draft cannot prove
- MetaTrader 4 and TradingView do not share one execution, data, or order model, so behavior can change even when both versions compile.
- Broker, symbol, session, timezone, history, and fill settings can change signals and backtest results on TradingView.
- Pineify can generate and revise a Pine Script draft, but the target platform remains the authority for compilation, loading, backtesting, and runtime behavior.
Use cases
When this conversion is useful
- Recreate an MT4 indicator on TradingView.
- Compare MQL4 EA signals in Pine Strategy Tester.
- Extract chart calculations from an EA and publish them as Pine alerts.
FAQ
MQL4 to Pine Script questions
Official references
- MQL4 event handling functions
MetaQuotes, checked 2026-08-10
- MQL4 OrderSend reference
MetaQuotes, checked 2026-08-10
- Pine Script execution model
TradingView, checked 2026-08-10
- Pine Script strategies
TradingView, checked 2026-08-10
Related converters
Browse all convertersBuild the Pine Script draft with its native model in view
Bring the complete source and your artifact, timing, data, and order requirements. Validate the result in TradingView.