PineScript v4 vs v5 vs v6 — Differences and Migration Guide

The same script in three versions

The simplest way to see the differences is to read the same idea in each version.

//@version=4
study("SMA cross", overlay=true)
len  = input(14, "Length", type=input.integer)
fast = sma(close, len)
slow = sma(close, len * 2)
plot(fast)
plot(slow)
htfClose = security(syminfo.tickerid, "D", close)

//@version=5
indicator("SMA cross", overlay=true)
len  = input.int(14, "Length")
fast = ta.sma(close, len)
slow = ta.sma(close, len * 2)
plot(fast)
plot(slow)
htfClose = request.security(syminfo.tickerid, "D", close)

//@version=6
strategy("SMA cross", overlay=true)
len  = input.int(14, "Length")
fast = ta.sma(close, len)
slow = ta.sma(close, len * 2)

// v6: conditions must be real booleans; no implicit number-to-bool casts
bool crossUp = ta.crossover(fast, slow)

// v6: the old `when=` argument of strategy.entry() is gone, use an if block
if crossUp
    strategy.entry("Long", strategy.long)

v4 → v5: namespaces and a new header

• study() became indicator().
• Built-in functions moved into namespaces: sma() → ta.sma(), rsi() → ta.rsi(), tostring() → str.tostring().
• security() became request.security().
• input(type=input.integer) was replaced by typed inputs such as input.int(), input.float() and input.bool().
• Libraries and exported functions were added, so shared code can be reused across scripts.

Most v4 → v5 work is mechanical renaming, which is why converters get you most of the way there.

v5 → v6: stricter and more predictable

• Booleans are strict. A bool can no longer be na, and numbers are not silently cast to booleans, so if myInt must be written as if myInt != 0.
• Dynamic requests. request.*() calls can take series string arguments, so one script can scan several symbols or timeframes.
• Removed arguments. The when argument of strategy.* order functions was removed in favour of ordinary if blocks.
• Lazy evaluation. and and or now short-circuit, which can change behaviour in scripts that relied on both sides always running.
• Better debugging. New log.info(), log.warning() and log.error() functions write to the Pine Logs panel.

Common errors when migrating

• Cannot use “series int” as a condition (or similar): an implicit number-to-boolean cast that v6 rejects.
• A strategy that suddenly places no trades after conversion because the removed when argument was silently dropped instead of rewritten.
• Different results because short-circuit evaluation skipped a function call that had side effects, such as building a series that other code relied on.
• Signals that shift by one bar after migration; always compare old and new versions bar by bar on the same chart.

Which version should you use?

• New scripts: v6, the current version, which receives new language features.
• Working v4 or v5 scripts: there is no need to migrate unless you need a newer feature, want to combine them with v6 code, or plan to hand the code to someone else.
• Converting to MQL4/MQL5: the source version matters less than clean logic, but older versions often hide repainting and look-ahead behaviour that must be found before conversion.

ExpertNevees works with PineScript v4, v5 and v6, including migration between versions and conversion to MetaTrader. See the PineScript guide and the conversion service.

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