Control use of JavaScript optimizers

Computer and userIntune-readyDefaultJavaScriptOptimizerSetting

Supported on Microsoft Edge version 134, Windows 7 or later

157.0.4341.42

Shown as of 157.0.4341.42, 5 Nov 2026. See it in the latest templates.

What it does

Allows you to set whether Microsoft Edge will run the v8 JavaScript engine with more advanced JavaScript optimizations enabled. Disabling JavaScript optimizations (by setting this policy's value to 2) will mean that Microsoft Edge may render web content more slowly. This policy can be overridden for specific URL patterns using the 'JavaScriptOptimizerAllowedForSites' (Allow JavaScript optimization on these sites) and 'JavaScriptOptimizerBlockedForSites' (Block JavaScript optimizations on these sites) policies. If you don't configure this policy, JavaScript optimizations are enabled. Policy options mapping: * AllowJavaScriptOptimizer (1) = Enable advanced JavaScript optimizations on all sites * BlockJavaScriptOptimizer (2) = Disable advanced JavaScript optimizations on all sites Use the preceding information when configuring this policy.

What it writes

Hive: HKEY_LOCAL_MACHINE or HKEY_CURRENT_USER
Registry key: Software\Policies\Microsoft\Edge

Options

Option	Type	Registry value	Allowed values
Control use of JavaScript optimizers	Drop-down list (enum)	`DefaultJavaScriptOptimizerSetting`	Enable advanced JavaScript optimizations on all sites`1` Disable advanced JavaScript optimizations on all sites`2`

Configure and deploy

Choose a state and the option values; the output below is generated from the template for exactly that.

Enabled · Computer · template defaults

Registry file (.reg)

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Edge]
"DefaultJavaScriptOptimizerSetting"=dword:00000001

PowerShell

$ErrorActionPreference = 'Stop'

function Set-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name,
        [Parameter(Mandatory = $true)][string] $PropertyType,
        [Parameter(Mandatory = $true)][object] $Value
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        New-Item -Path $Path -Force | Out-Null
    }

    New-ItemProperty -LiteralPath $Path -Name $Name -PropertyType $PropertyType -Value $Value -Force | Out-Null
}

function Remove-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name
    )

    if (Test-Path -LiteralPath $Path) {
        Remove-ItemProperty -LiteralPath $Path -Name $Name -Force -ErrorAction SilentlyContinue
    }
}

function Clear-RegistryKeyValues {
    param(
        [Parameter(Mandatory = $true)][string] $Path
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return
    }

    foreach ($propertyName in (Get-Item -LiteralPath $Path).Property) {
        Remove-ItemProperty -LiteralPath $Path -Name $propertyName -Force -ErrorAction SilentlyContinue
    }
}

# Policy: Control use of JavaScript optimizers
# Name: DefaultJavaScriptOptimizerSetting
# Scope: Machine
# State: Enabled
# Source: msedge.admx

Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Edge' -Name 'DefaultJavaScriptOptimizerSetting' -PropertyType 'DWord' -Value 1

The OMA-URI is an inferred ADMX-backed Policy CSP candidate derived from the source ADMX file name and policy name.
Some Microsoft policies use built-in Policy CSP pages whose area names don't match the ADMX file name, so verify the candidate against Microsoft Learn before deployment.
The generated payload is incomplete because one or more ADMX element values were not supplied: DefaultJavaScriptOptimizerSetting

ADMX profile candidate (OMA-URI)

./Device/Vendor/MSFT/Policy/Config/ADMX_msedge/DefaultJavaScriptOptimizerSetting

Intune remediation scripts

Detection

$ErrorActionPreference = 'Stop'
$reasons = [System.Collections.Generic.List[string]]::new()

function Test-RegistryValueExists {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return $false
    }

    return $null -ne (Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction SilentlyContinue)
}

function Test-RegistryValueEquals {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name,
        [Parameter(Mandatory = $true)][string] $Kind,
        [Parameter(Mandatory = $true)][object] $Expected
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return $false
    }

    $valueObject = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction SilentlyContinue
    if ($null -eq $valueObject) {
        return $false
    }

    $actual = $valueObject.$Name
    switch ($Kind) {
        'String' { return [string]$actual -ceq [string]$Expected }
        'ExpandString' { return [string]$actual -ceq [string]$Expected }
        'DWord' { return [uint32]$actual -eq [uint32]$Expected }
        'QWord' {
            $actualBits = if ($actual -is [uint64]) { $actual } else { [BitConverter]::ToUInt64([BitConverter]::GetBytes([int64]$actual), 0) }
            $expectedBits = if ($Expected -is [uint64]) { $Expected } else { [BitConverter]::ToUInt64([BitConverter]::GetBytes([int64]$Expected), 0) }
            return $actualBits -eq $expectedBits
        }
        'MultiString' {
            $actualArray = @($actual)
            $expectedArray = @($Expected)
            if ($actualArray.Count -ne $expectedArray.Count) { return $false }
            for ($index = 0; $index -lt $actualArray.Count; $index++) {
                if ([string]$actualArray[$index] -cne [string]$expectedArray[$index]) { return $false }
            }
            return $true
        }
        'Binary' {
            $actualArray = [byte[]]$actual
            $expectedArray = [byte[]]$Expected
            if ($actualArray.Length -ne $expectedArray.Length) { return $false }
            for ($index = 0; $index -lt $actualArray.Length; $index++) {
                if ($actualArray[$index] -ne $expectedArray[$index]) { return $false }
            }
            return $true
        }
        default { return [string]$actual -ceq [string]$Expected }
    }
}

# Policy: Control use of JavaScript optimizers
# Name: DefaultJavaScriptOptimizerSetting
# Scope: Machine
# State: Enabled
# Source: msedge.admx

$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Edge' -Name 'DefaultJavaScriptOptimizerSetting' -Kind 'DWord' -Expected 1
if (-not $isMatch) {
    $reasons.Add('Value mismatch: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Edge\DefaultJavaScriptOptimizerSetting') | Out-Null
}

if ($reasons.Count -eq 0) {
    Write-Output 'Compliant'
    exit 0
}

$reasons | ForEach-Object { Write-Output $_ }
exit 1

Remediation

$ErrorActionPreference = 'Stop'

function Set-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name,
        [Parameter(Mandatory = $true)][string] $PropertyType,
        [Parameter(Mandatory = $true)][object] $Value
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        New-Item -Path $Path -Force | Out-Null
    }

    New-ItemProperty -LiteralPath $Path -Name $Name -PropertyType $PropertyType -Value $Value -Force | Out-Null
}

function Remove-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name
    )

    if (Test-Path -LiteralPath $Path) {
        Remove-ItemProperty -LiteralPath $Path -Name $Name -Force -ErrorAction SilentlyContinue
    }
}

function Clear-RegistryKeyValues {
    param(
        [Parameter(Mandatory = $true)][string] $Path
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return
    }

    foreach ($propertyName in (Get-Item -LiteralPath $Path).Property) {
        Remove-ItemProperty -LiteralPath $Path -Name $propertyName -Force -ErrorAction SilentlyContinue
    }
}

# Policy: Control use of JavaScript optimizers
# Name: DefaultJavaScriptOptimizerSetting
# Scope: Machine
# State: Enabled
# Source: msedge.admx

Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Edge' -Name 'DefaultJavaScriptOptimizerSetting' -PropertyType 'DWord' -Value 1

History 47 retained releases

150.0.4078.8016 Jul 2026
- Already present in the first release ChangeIntel keeps.

46 later releases left it unchanged.

Template

Internal name: DefaultJavaScriptOptimizerSetting
Namespace: Microsoft.Policies.Edge
Template file: msedge.admx
Release: Microsoft Edge 157.0.4341.42 · file set 0c38d160a969619e…

Definition, editor controls and support

Definition

<policy class="Both" displayName="$(string.DefaultJavaScriptOptimizerSetting)" explainText="$(string.DefaultJavaScriptOptimizerSetting_Explain)" key="Software\Policies\Microsoft\Edge" name="DefaultJavaScriptOptimizerSetting" presentation="$(presentation.DefaultJavaScriptOptimizerSetting)" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Microsoft.Policies.Edge:ContentSettings" />
      <supportedOn ref="Microsoft.Policies.Edge:SUPPORTED_WIN7_V134" />
      <elements>
        <enum id="DefaultJavaScriptOptimizerSetting" valueName="DefaultJavaScriptOptimizerSetting">
          <item displayName="$(string.DefaultJavaScriptOptimizerSetting_AllowJavaScriptOptimizer)">
            <value>
              <decimal value="1" />
            </value>
          </item>
          <item displayName="$(string.DefaultJavaScriptOptimizerSetting_BlockJavaScriptOptimizer)">
            <value>
              <decimal value="2" />
            </value>
          </item>
        </enum>
      </elements>
    </policy>

Editor controls

<presentation id="DefaultJavaScriptOptimizerSetting" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions"><dropdownList refId="DefaultJavaScriptOptimizerSetting">Control use of JavaScript optimizers</dropdownList></presentation>

Supported platforms and category

Microsoft.Policies.Edge:category:ContentSettings
<category displayName="$(string.ContentSettings_group)" name="ContentSettings" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Microsoft.Policies.Edge:microsoft_edge" />
    </category>
Microsoft.Policies.Edge:category:microsoft_edge
<category displayName="$(string.microsoft_edge)" name="microsoft_edge" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
Microsoft.Policies.Edge:definition:SUPPORTED_WIN7_V134
<definition displayName="$(string.SUPPORTED_WIN7_V134)" name="SUPPORTED_WIN7_V134" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
Microsoft.Policies.Edge:category:ContentSettings
<category displayName="$(string.ContentSettings_group)" name="ContentSettings" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Microsoft.Policies.Edge:microsoft_edge" />
    </category>
<strings><string id="Microsoft.Policies.Edge:ContentSettings_group">Content settings</string></strings>
Microsoft.Policies.Edge:category:microsoft_edge
<category displayName="$(string.microsoft_edge)" name="microsoft_edge" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="Microsoft.Policies.Edge:microsoft_edge">Microsoft Edge</string></strings>
Microsoft.Policies.Edge:definition:SUPPORTED_WIN7_V134
<definition displayName="$(string.SUPPORTED_WIN7_V134)" name="SUPPORTED_WIN7_V134" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="Microsoft.Policies.Edge:SUPPORTED_WIN7_V134">Microsoft Edge version 134, Windows 7 or later</string></strings>