UGameplayStatics::FlushLevelStreaming

function Engine Blueprint Since 4.0

#include "Kismet/GameplayStatics.h"

Access: public Specifiers: staticUFUNCTIONBlueprintCallable

Description

Blocks the game thread until all pending level streaming operations (loads, unloads, visibility changes) are fully complete. Used to guarantee a clean streaming state before a cutscene or gameplay event.

Caveats & Gotchas

• This function blocks the game thread entirely — it will cause a hard frame hitch proportional to the total remaining streaming work. Never call it during normal gameplay; restrict it to loading screens or cinematic transitions.
• Does not cancel in-flight async I/O; it simply spins the streaming system until all queued state changes are resolved. On large open worlds with many streaming levels this can take several seconds.
• Calling FlushLevelStreaming while a level transition (OpenLevel) is already in progress has undefined behaviour — the travel may complete before flushing finishes, leaving the streaming system in an unexpected state.

Signature

static ENGINE_API void FlushLevelStreaming(const UObject* WorldContextObject);

Parameters

Name	Type	Description	Default
WorldContextObject	const UObject*	Any object in the world to use as context.	—

Return Type

void

Example

Guarantee all levels are loaded before starting a cutscene C++

// Trigger all desired level loads first
UGameplayStatics::LoadStreamLevel(this, FName("BossArena"), true, false, LatentInfo);
// Then flush to ensure they are ready before the cutscene starts
UGameplayStatics::FlushLevelStreaming(this);
StartCutscene();

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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