Blocked websites
Verified with Mozilla Firefox v8.2 — updated on July 10, 2026
Supported on: Firefox 60 or later, Firefox 60 ESR or later
Path in the GPO console
Computer Configuration\Administrative Templates\Mozilla\Firefox User Configuration\Administrative Templates\Mozilla\Firefox Description
If this policy is enabled, you can specify match patterns that indicate sites to be blocked. The match patterns are documented at https://developer.mozilla.org/en-us/Add-ons/WebExtensions/Match_patterns. There is a 1000 entry limit. If this policy is disabled or not configured, no websites are blocked.
Registry
HKLM
Software\Policies\Mozilla\WebsiteFilter\Block HKCU
Software\Policies\Mozilla\WebsiteFilter\Block Export Builder
BETAConfigure the state, scope and options, then generate .reg, PowerShell, Intune and SCCM outputs — or add the setting to a multi-setting collection.
These exports write the registry — this is not a managed GPO. ⓘ
Applying both scopes creates an ambiguous configuration (computer takes precedence over user). Only do this intentionally.
.reg file
Windows Registry Editor Version 5.00
; Exported from gporais.com
; Policy: Blocked websites
; State: Enabled
; Scope: Computer (HKLM)
; Supported on: Firefox 60 or later, Firefox 60 ESR or later
[HKEY_LOCAL_MACHINE\Software\Policies\Mozilla\Firefox\WebsiteFilter\Block]
; List values: enter one value per line in the builder UI.More formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: Blocked websites
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Firefox 60 or later, Firefox 60 ESR or later
$path = 'HKLM:\Software\Policies\Mozilla\Firefox\WebsiteFilter\Block'
New-Item -Path $path -Force | Out-Null
# List values: enter one value per line in the builder UI.Intune XML
No direct Policy CSP / OMA-URI mapping for this policy. Use the Intune Remediation tab, or ingest the ADMX in Intune.Intune Remediation
# === Detection script ===
# Exported from gporais.com
# Policy: Blocked websites
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Firefox 60 or later, Firefox 60 ESR or later
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
# HKLM:\Software\Policies\Mozilla\Firefox\WebsiteFilter\Block: List values: enter one value per line in the builder UI.
# No testable registry values are available for this state.
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Blocked websites
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Firefox 60 or later, Firefox 60 ESR or later
$path = 'HKLM:\Software\Policies\Mozilla\Firefox\WebsiteFilter\Block'
New-Item -Path $path -Force | Out-Null
# List values: enter one value per line in the builder UI.SCCM scripts
# Exported from gporais.com
# Policy: Blocked websites
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Firefox 60 or later, Firefox 60 ESR or later
# SCCM Configuration Item guidance:
# Create a Configuration Item of type "Setting: Script".
# Discovery script: use the Detection script below.
# Remediation script: use the Remediation script below.
# Compliance rule: the Discovery script output equals 'Compliant'.
# === Detection script ===
# Exported from gporais.com
# Policy: Blocked websites
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Firefox 60 or later, Firefox 60 ESR or later
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
# HKLM:\Software\Policies\Mozilla\Firefox\WebsiteFilter\Block: List values: enter one value per line in the builder UI.
# No testable registry values are available for this state.
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Blocked websites
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Firefox 60 or later, Firefox 60 ESR or later
$path = 'HKLM:\Software\Policies\Mozilla\Firefox\WebsiteFilter\Block'
New-Item -Path $path -Force | Out-Null
# List values: enter one value per line in the builder UI.Building a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.