Enable Site Isolation for specified origins

What it does

Specify a list of origins that run in a dedicated process. On Android, this policy only works on devices with sufficient memory (strictly more than 3.2GB RAM), as isolating too many sites on resource-constrained devices may cause performance problems. For resource-constrained Android devices, please use IsolateOriginsShortlist instead. Devices with less than 1GB memory are not recommended to configure any process isolation specifically. Each named origin's process will only be allowed to contain documents from that origin and its subdomains. For example, specifying https://a1.example.com/ allows https://a2.a1.example.com/ in the same process, but not https://example.com or https://b.example.com. Since Brave 77, you can also specify a range of origins to isolate using a wildcard. For example, specifying https://[*.]corp.example.com will give every origin underneath https://corp.example.com its own dedicated process, including https://corp.example.com itself, https://a1.corp.example.com, and https://a2.a1.corp.example.com. Note that all sites (i.e., scheme plus eTLD+1, such as https://example.com) are already isolated by default on Desktop platforms, as noted in the SitePerProcess policy. This IsolateOrigins policy is useful to isolate specific origins at a finer granularity (e.g., https://a.example.com). Note that Android isolates certain sensitive sites by default starting in Brave version 77, and this policy extends that mode to isolate specific additional origins. Also note that origins isolated by this policy will be unable to script other origins in the same site, which is otherwise possible if two same-site documents modify their document.domain values to match. Administrators should confirm this uncommon behavior is not used on an origin before isolating it. Setting the policy to an empty string or leaving it unset means site isolation won't be required for any specific origins. Users can still turn on process isolation manually, through the command line flag. Example value: https://a.example.com/,https://othersite.org/,https://[*.]corp.example.com

What it writes

Hive

HKEY_LOCAL_MACHINE or HKEY_CURRENT_USER

Registry key

Software\Policies\BraveSoftware\Brave

Options

Configure and deploy

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

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\Software\Policies\BraveSoftware\Brave]
"IsolateOrigins"=""

$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: Enable Site Isolation for specified origins
# Name: IsolateOrigins
# Scope: Machine
# State: Enabled
# Source: brave.admx

Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\BraveSoftware\Brave' -Name 'IsolateOrigins' -PropertyType 'String' -Value ''

./Device/Vendor/MSFT/Policy/Config/ADMX_brave/IsolateOrigins

$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: Enable Site Isolation for specified origins
# Name: IsolateOrigins
# Scope: Machine
# State: Enabled
# Source: brave.admx

$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\BraveSoftware\Brave' -Name 'IsolateOrigins' -Kind 'String' -Expected ''
if (-not $isMatch) {
    $reasons.Add('Value mismatch: HKEY_LOCAL_MACHINE\Software\Policies\BraveSoftware\Brave\IsolateOrigins') | Out-Null
}

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

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

$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: Enable Site Isolation for specified origins
# Name: IsolateOrigins
# Scope: Machine
# State: Enabled
# Source: brave.admx

Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\BraveSoftware\Brave' -Name 'IsolateOrigins' -PropertyType 'String' -Value ''

History 44 retained releases

1. 1.93.12930 Jul 2026
   • Description [removed: Setting the][added: Specify a list of origins that run in a …] policy [removed: means each of the named origins in a comma-…][added: only works on devices with sufficient memor…]Each named origin's process will only be al…[added: Note that Android isolates certain sensitiv…]Also note that origins isolated by this pol…[removed: off][added: an empty string] or leaving it unset [removed: lets users change this setting. Note: For Android, use][added: means site isolation won't be required for any specific origins. …] the [removed: IsolateOriginsAndroid policy instead.][added: command line flag.]…
     Whole description, marked

     [removed: Setting the][added: Specify a list of origins that run in a dedicated process. On Android, this] policy [removed: means each of the named origins in a comma-separated list runs in a dedicated process. ][added: only works on devices with sufficient memory (strictly more than 3.2GB RAM), as isolating too many sites on resource-constrained devices may cause performance problems. For resource-constrained Android devices, please use IsolateOriginsShortlist instead. Devices with less than 1GB memory are not recommended to configure any process isolation specifically. ]Each named origin's process will only be allowed to contain documents from that origin and its subdomains. For example, specifying https://a1.example.com/ allows https://a2.a1.example.com/ in the same process, but not https://example.com or https://b.example.com. Since Brave 77, you can also specify a range of origins to isolate using a wildcard. For example, specifying https://[*.]corp.example.com will give every origin underneath https://corp.example.com its own dedicated process, including https://corp.example.com itself, https://a1.corp.example.com, and https://a2.a1.corp.example.com. Note that all sites (i.e., scheme plus eTLD+1, such as https://example.com) are already isolated by default on Desktop platforms, as noted in the SitePerProcess policy. This IsolateOrigins policy is useful to isolate specific origins at a finer granularity (e.g., https://a.example.com). [added: Note that Android isolates certain sensitive sites by default starting in Brave version 77, and this policy extends that mode to isolate specific additional origins. ]Also note that origins isolated by this policy will be unable to script other origins in the same site, which is otherwise possible if two same-site documents modify their document.domain values to match. Administrators should confirm this uncommon behavior is not used on an origin before isolating it. Setting the policy to [removed: off][added: an empty string] or leaving it unset [removed: lets users change this setting. Note: For Android, use][added: means site isolation won't be required for any specific origins. Users can still turn on process isolation manually, through] the [removed: IsolateOriginsAndroid policy instead.][added: command line flag.] Example value: https://a.example.com/,https://othersite.org/,https://[*.]corp.example.com

2. 1.88.13214 Mar 2026
   • Already present in the first release ChangeIntel keeps.

42 later releases left it unchanged.

Template

Internal name

IsolateOrigins

Namespace

BraveSoftware.Policies.Brave

Template file

brave.admx

Release

Brave Browser 1.97.59 · file set d6401efd8c1937d9…

<policy class="Both" displayName="$(string.IsolateOrigins)" explainText="$(string.IsolateOrigins_Explain)" key="Software\Policies\BraveSoftware\Brave" name="IsolateOrigins" presentation="$(presentation.IsolateOrigins)" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="BraveSoftware.Policies.Brave:brave" />
      <supportedOn ref="BraveSoftware.Policies.Brave:SUPPORTED_WIN7" />
      <elements>
        <text id="IsolateOrigins" maxLength="1000000" valueName="IsolateOrigins" />
      </elements>
    </policy>

<presentation id="IsolateOrigins" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions"><textBox refId="IsolateOrigins"><label>Enable Site Isolation for specified origins</label></textBox></presentation>

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>