Learn about the new permission prompt for sites that connect to local networks.
Published: June 9, 2025

Chrome is adding a new permission prompt for sites that make connections to a user's local network as part of the draft Local Network Access specification. The aim is to protect users from cross-site request forgery (CSRF) attacks targeting routers and other devices on private networks, and to reduce the ability of sites to use these requests to fingerprint the user's local network.

To understand how this change impacts the web ecosystem, the Chrome team is looking for feedback from developers who build web applications that rely on making connections to a user's local network or to software running locally on the user's machine. From Chrome 138, you can opt-in to these new restrictions by going to chrome://flags/#local-network-access-check and setting the flag to "Enabled (Blocking)".

Note: Chrome previously experimented with restricting access to local network devices with Private Network Access, which required CORS preflights where the target device opted in to being connected to, instead of gating all local network accesses behind a permission prompt. Local Network Access replaces that effort, after PNA was put on hold. Thank you to everyone who helped test PNA and provide feedback to us—it has been incredibly valuable and helped guide us to our new Local Network Access permission approach.
What is Local Network Access?
Local Network Access restricts the ability of websites to send requests to servers on a user's local network (including servers running locally on the user's machine), requiring the user grant the site permission before such requests can be made. The ability to request this permission is restricted to secure contexts.

A prompt with the text 'Look for and connect to any device on your local network.'
Example of Chrome's Local Network Access permission prompt.
Many other platforms, such as Android, iOS, and MacOS have a local network access permission. For example, you may have granted this permission to access the local network to the Google Home app when setting up new Google TV and Chromecast devices.

What kinds of requests are affected?
For the first milestone of Local Network Access, we consider a "local network request" to be any request from the public network to a local network or loopback destination.

A local network is any destination that resolves to the private address space defined in Section 3 of RFC1918 in IPv4 (e.g., 192.168.0.0/16), an IPv4-mapped IPv6 address where the mapped IPv4 address is itself private, or an IPv6 address outside the ::1/128, 2000::/3, and ff00::/8 subnets.

Loopback is any destination that resolves to the "loopback" space (127.0.0.0/8) defined in section 3.2.1.3 of RFC1122 of IPv4, the "link-local" space (169.254.0.0/16) defined in RFC3927 of IPv4, the "Unique Local Address" prefix (fcc00::/7) defined in Section 3 of RFC4193 of IPv6, or the "link-local" prefix (fe80::/10) defined in section 2.5.6 of RFC4291 of IPv6.

A public network is any other destination.

Note: In the future, we plan to extend these protections to cover all cross-origins requests going to destinations on the local network. This would include requests from a local server (for example, https://router.local) to other servers on the local network, or from a local server to localhost.
Because the local network access permission is restricted to secure contexts, and it can be difficult to migrate local network devices to HTTPS, the permission-gated local network requests will now be exempted from mixed content checks if Chrome knows that the requests will be going to the local network before resolving the destination. Chrome knows a request is going to the local network if:

The request hostname is a private IP literal (e.g., 192.168.0.1).
The request hostname is a .local domain.
The fetch() call is annotated with the option targetAddressSpace: "local".

// Example 1: Private IP literal is exempt from mixed content.
fetch("http://192.168.0.1/ping");

// Example 2: .local domain is exempt from mixed content.
fetch("http://router.local/ping");

// Example 3: Public domain is not exempt from mixed content,
// even if it resolves to a local network address.
fetch("http://example.com/ping");

// Example 4: Adding the targetAddressSpace option flags that
// the request will go to the local network, and is thus exempt
// from mixed content.
fetch("http://example.com/ping", {
targetAddressSpace: "local",
});
What's changing in Chrome
Chrome 138
Our initial version of Local Network Access is ready for opt-in testing in Chrome 138. Users can enable the new permission prompt by setting chrome://flags#local-network-access-check to "Enabled (Blocking)". This supports triggering the Local Network Access permission prompt for requests initiated using the JavaScript fetch() API, subresource loading, and subframe navigation.

A demo site is available at https://local-network-access-testing.glitch.me/ for triggering different forms of local network requests.

Known issues and limitations
The new permission prompt is currently only implemented on Desktop Chrome. We are actively working on porting it to Android Chrome. (Tracked in crbug.com/400455013.)
WebSockets (crbug.com/421156866), WebTransport (crbug.com/421216834), and WebRTC (crbug.com/421223919) connections to the local network are not yet gated on the LNA permission.
Local network requests from Service Workers currently require that the service worker's origin has previously been granted the Local Network Access permission.
If your application makes local network requests from a service worker, you will currently need to separately trigger a local network request from your application in order to trigger the permission prompt. (We are working on a way for workers to trigger the permission prompt if there is an active document available—see crbug.com/404887282.)
Chrome 139 and beyond
Our intent is to ship Local Network Access as soon as possible. Recognizing that some sites may need additional time to be updated with Local Network Access annotations, we will add an Origin Trial to let sites temporarily opt-out of the secure contexts requirement before we ship Local Network Access by default. This should provide a clearer migration path for developers, especially if you rely on accessing local network resources over HTTP (as these requests would be blocked as mixed content if requested from an HTTPS page in browsers that don't yet support the Local Network Access mixed content exemption).

We will also be adding a Chrome enterprise policy for controlling which sites can and cannot make local network requests (pre-granting or pre-denying the permission to those sites). This will allow managed Chrome installations, such as those in corporate settings, to avoid showing the warning for known intended use cases, or to further lock down and prevent sites from being able to request the permission at all.

We plan to continue integrating the Local Network Access permission with different features that can send requests to the local network. For example, we plan to ship Local Network Access for WebSockets, WebTransport, and WebRTC connections soon.

We will share more information as we get closer to being able to fully launch Local Network Access in Chrome.