---
title: Optimize AppLocker performance (Windows)
description: This topic for IT professionals describes how to optimize AppLocker policy enforcement.
ms.assetid: a20efa20-bc98-40fe-bd81-28ec4905e0f6
ms.reviewer: 
ms.author: dansimp
ms.prod: m365-security
ms.mktglfcycl: deploy
ms.sitesec: library
ms.pagetype: security
ms.localizationpriority: medium
author: dansimp
manager: dansimp
audience: ITPro
ms.collection: M365-security-compliance
ms.topic: conceptual
ms.date: 09/21/2017
ms.technology: mde
---

# Optimize AppLocker performance

**Applies to**

- Windows 10
- Windows 11
- Windows Server 2016 and above

>[!NOTE]
>Some capabilities of Windows Defender Application Control are only available on specific Windows versions. Learn more about the [Windows Defender Application Control feature availability](/windows/security/threat-protection/windows-defender-application-control/feature-availability).

This topic for IT professionals describes how to optimize AppLocker policy enforcement.

## Optimization of Group Policy

AppLocker policies can be implemented by organization unit (OU) using Group Policy. If so, your Group Policy infrastructure should be optimized and retested for performance when AppLocker policies are added to existing Group Policy Objects (GPOs) or new GPOs are created, as you do with adding any policies to your GPOs.

For more info, see the [Optimizing Group Policy Performance](/previous-versions/technet-magazine/cc137720(v=msdn.10)) article in TechNet Magazine.

### AppLocker rule limitations

The more rules per GPO, the longer AppLocker requires for evaluation. There is no set limitation on the number of rules per GPO, but the number of rules that can fit into a 100 MB GPO varies based on the complexity of the rule, such as the number of file hashes included in a single file hash 
condition.

### Using the DLL rule collection

When the DLL rule collection is enabled, AppLocker must check each DLL that an application loads. The more DLLs, the longer AppLocker requires to complete the evaluation.