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Block JavaScript optimizations on these sites

Verified with Google Chrome — updated on July 10, 2026

Supported on: Microsoft Windows 7 or later

Path in the GPO console

Computer Configuration\Administrative Templates\Google\Google Chrome\Content settings

Description

Allows you to set a list of site url patterns that specify sites for which advanced JavaScript optimizations are disabled. Disabling JavaScript optimizations will mean that Google Chrome may render web content more slowly. For detailed information on valid url patterns, please see https://chromeenterprise.google/policies/url-patterns. Wildcards, *, are allowed. JavaScript optimization policy exceptions will only be enforced at a site granularity (eTLD+1). A policy set for only subdomain.site.com will not correctly apply to site.com or subdomain.site.com since they both resolve to the same eTLD+1 (site.com) for which there is no policy. In this case, policy must be set on site.com to apply correctly for both site.com and subdomain.site.com. This policy applies on a frame-by-frame basis and not based on top level origin url alone, so e.g. if site-one.com is listed in the JavaScriptOptimizerBlockedForSites policy but site-one.com loads a frame containing site-two.com then site-one.com will have JavaScript optimizations disabled, but site-two.com will use the policy from DefaultJavaScriptOptimizerSetting, if set, or default to JavaScript optimizations enabled. Blocklist entries have higher priority than allowlist entries, which in turn have higher priority than the configured default value. If this policy is not set for a site then the policy from DefaultJavaScriptOptimizerSetting applies to the site, if set, otherwise JavaScript optimization is enabled for the site. Example value: [*.]example.edu

Registry

HKLM Software\Policies\Google\Chrome
HKCU Software\Policies\Google\Chrome

More options available

Options

Block JavaScript optimizations on these sites
List (registry values) list
- list under Software\Policies\Google\Chrome\JavaScriptOptimizerBlockedForSites

Export Builder

BETA

Configure 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.

Scope

.reg file

Windows Registry Editor Version 5.00

; Exported from gporais.com
; Policy: Block JavaScript optimizations on these sites
; State: Enabled
; Scope: Computer (HKLM)
; Supported on: Microsoft Windows 7 or later

[HKEY_LOCAL_MACHINE\Software\Policies\Google\Chrome\JavaScriptOptimizerBlockedForSites]
; List values: enter one value per line in the builder UI.
More formats (PowerShell, Intune, SCCM)

PowerShell

# Exported from gporais.com
# Policy: Block JavaScript optimizations on these sites
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Windows 7 or later

$path = 'HKLM:\Software\Policies\Google\Chrome\JavaScriptOptimizerBlockedForSites'
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.

Open the Builder

Embed this policy on your site

What to embed
Theme

Adds one script line: the theme follows your site’s appearance and the height fits the content. If your site blocks scripts, the embed follows the visitor’s system theme.

Preview