Lookahead gives a limiter time to catch fast peaks before they pass.
Definition
A short preview buffer
Limiter lookahead delays the output slightly so the processor can see incoming peaks before they reach the gain stage. That preview helps it reduce level before the peak clips.
More lookahead can make peak control cleaner, but it also adds latency and can soften very sharp transients.
Tradeoff
Cleaner control, different feel
Low or no lookahead can feel punchier, but fast peaks may distort or slip through. Higher lookahead can sound smoother, but the leading edge may feel less aggressive.
The best setting depends on whether the limiter is solving overloads, adding loudness, or preserving transient feel.
Check
Confirm the peak result
After changing lookahead, check sample peak and true peak because the limiter behavior may change even when the ceiling stays the same.
Meter Core shows peak and loudness readings together so lookahead changes can be judged by both safety and feel.