Brave Software › Brave
Allow SpeculationRules prefetch to ServiceWorker-controlled URLs
Supported on Microsoft Windows 7 or later
Shown as of 1.89.145, 29 Apr 2026. See it in the latest templates.
What it does
SpeculationRules prefetch can be issued to URLs that are controlled by ServiceWorker. However, legacy code did not allow it and canceled the prefetch requests. This policy enables to control the behavior. Setting this policy to Enabled or not set allows SpeculationRules prefetch to ServiceWorker-controlled URLs (if the PrefetchServiceWorker feature flag is enabled). This is the current default behavior and is aligned with the specifications. Setting this policy to Disabled disallows SpeculationRules prefetch to ServiceWorker-controlled URLs. This is the legacy behavior. This policy is intended to be temporary and will be removed in the future.
What it writes
- Hive
- HKEY_LOCAL_MACHINE or HKEY_CURRENT_USER
- Registry key
Software\Policies\BraveSoftware\Brave- Value name
PrefetchWithServiceWorkerEnabled- When enabled
- DWORD 1
- When disabled
- DWORD 0
Configure and deploy
Choose a state; 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\BraveSoftware\Brave]
"PrefetchWithServiceWorkerEnabled"=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: Allow SpeculationRules prefetch to ServiceWorker-controlled URLs
# Name: PrefetchWithServiceWorkerEnabled
# Scope: Machine
# State: Enabled
# Source: brave.admx
Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\BraveSoftware\Brave' -Name 'PrefetchWithServiceWorkerEnabled' -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.
ADMX profile candidate (OMA-URI)
./Device/Vendor/MSFT/Policy/Config/ADMX_brave/PrefetchWithServiceWorkerEnabledADMX SyncML candidate
<SyncML xmlns="SYNCML:SYNCML1.2">
<SyncBody>
<Replace>
<CmdID>1</CmdID>
<Item>
<Meta>
<Format>chr</Format>
<Type>text/plain</Type>
</Meta>
<Target>
<LocURI>./Device/Vendor/MSFT/Policy/Config/ADMX_brave/PrefetchWithServiceWorkerEnabled</LocURI>
</Target>
<Data><enabled/></Data>
</Item>
</Replace>
<Final/>
</SyncBody>
</SyncML>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]$Expected }
'QWord' { return [uint64]$actual -eq [uint64]$Expected }
'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: Allow SpeculationRules prefetch to ServiceWorker-controlled URLs
# Name: PrefetchWithServiceWorkerEnabled
# Scope: Machine
# State: Enabled
# Source: brave.admx
$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\BraveSoftware\Brave' -Name 'PrefetchWithServiceWorkerEnabled' -Kind 'DWord' -Expected 1
if (-not $isMatch) {
$reasons.Add('Value mismatch: HKEY_LOCAL_MACHINE\Software\Policies\BraveSoftware\Brave\PrefetchWithServiceWorkerEnabled') | Out-Null
}
if ($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 $propertyName -Force -ErrorAction SilentlyContinue
}
}
# Policy: Allow SpeculationRules prefetch to ServiceWorker-controlled URLs
# Name: PrefetchWithServiceWorkerEnabled
# Scope: Machine
# State: Enabled
# Source: brave.admx
Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\BraveSoftware\Brave' -Name 'PrefetchWithServiceWorkerEnabled' -PropertyType 'DWord' -Value 1
History 44 retained releases
- 1.88.13214 Mar 2026
- Already present in the first release ChangeIntel keeps.
43 later releases left it unchanged.
Template
- Internal name
PrefetchWithServiceWorkerEnabled- Namespace
BraveSoftware.Policies.Brave- Template file
brave.admx- Release
- Brave Browser 1.89.145 · file set
770be8c14e479ef4…
Definition, editor controls and support
Definition
<policy class="Both" displayName="$(string.PrefetchWithServiceWorkerEnabled)" explainText="$(string.PrefetchWithServiceWorkerEnabled_Explain)" key="Software\Policies\BraveSoftware\Brave" name="PrefetchWithServiceWorkerEnabled" presentation="$(presentation.PrefetchWithServiceWorkerEnabled)" valueName="PrefetchWithServiceWorkerEnabled" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="BraveSoftware.Policies.Brave:brave" />
<supportedOn ref="BraveSoftware.Policies.Brave:SUPPORTED_WIN7" />
<enabledValue>
<decimal value="1" />
</enabledValue>
<disabledValue>
<decimal value="0" />
</disabledValue>
</policy>Editor controls
<presentation id="PrefetchWithServiceWorkerEnabled" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />Supported platforms and category
BraveSoftware.Policies.Brave:category:Cat_Brave
<category displayName="$(string.Cat_Brave)" name="Cat_Brave" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
BraveSoftware.Policies.Brave:category:brave
<category displayName="$(string.brave)" name="brave" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="BraveSoftware.Policies.Brave:Cat_Brave" />
</category>
BraveSoftware.Policies.Brave:definition:SUPPORTED_WIN7
<definition displayName="$(string.SUPPORTED_WIN7)" name="SUPPORTED_WIN7" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
BraveSoftware.Policies.Brave:category:Cat_Brave
<category displayName="$(string.Cat_Brave)" name="Cat_Brave" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="BraveSoftware.Policies.Brave:Cat_Brave">Brave Software</string></strings>
BraveSoftware.Policies.Brave:category:brave
<category displayName="$(string.brave)" name="brave" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="BraveSoftware.Policies.Brave:Cat_Brave" />
</category>
<strings><string id="BraveSoftware.Policies.Brave:brave">Brave</string></strings>
BraveSoftware.Policies.Brave:definition:SUPPORTED_WIN7
<definition displayName="$(string.SUPPORTED_WIN7)" name="SUPPORTED_WIN7" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="BraveSoftware.Policies.Brave:SUPPORTED_WIN7">Microsoft Windows 7 or later</string></strings>