Intent to Ship: Web serial over Bluetooth on Android

[Chromestatus]

Contact emails

xu...@google.com

Explainer

None

Specification

https://wicg.github.io/serial

Design docs

https://web.dev/serial

Summary

This feature allows web pages and web apps to connect to serial ports over Bluetooth on Android devices. Chrome on Android now supports Web Serial API over Bluetooth RFCOMM. Existing enterprise policies (DefaultSerialGuardSetting, SerialAllowAllPortsForUrls, SerialAllowUsbDevicesForUrls, SerialAskForUrls and SerialBlockedForUrls) on other platforms are enabled in future_on states for Android. All policies except SerialAllowUsbDevicesForUrls will be enabled after the feature is enabled. SerialAllowUsbDevicesForUrls will be enabled in a future launch after Android provides system level support of wired serial ports.

Blink component

Blink>Serial

TAG review

None

TAG review status

Not applicable

Risks

Interoperability and Compatibility

None

Gecko: Neutral (https://mozilla.github.io/standards-positions/#webserial)

WebKit: Negative (https://webkit.org/tracking-prevention)

Web developers: No signals

Other signals:

WebView application risks

Does this intent deprecate or change behavior of existing APIs, such that it has potentially high risk for Android WebView-based applications?

None

Debuggability

None

Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?

No

This is a catch-up work for Android, but the Webview embedder will not have it, similar to other device features.

Is this feature fully tested by web-platform-tests?

No

Flag name on about://flags

None

Finch feature name

BluetoothRfcommAndroid

Rollout plan

Will ship enabled for all users

Requires code in //chrome?

False

Tracking bug

https://g-issues.chromium.org/issues/375245353

Launch bug

https://launch.corp.google.com/launch/4360426

Estimated milestones

Shipping on Android

137

Anticipated spec changes

Open questions about a feature may be a source of future web compat or interop issues. Please list open issues (e.g. links to known github issues in the project for the feature specification) whose resolution may introduce web compat/interop risk (e.g., changing to naming or structure of the API in a non-backward-compatible way).

None

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/5139978918821888?gate=6303617830879232

This intent message was generated by Chrome Platform Status.

[Rupert Wiser]

Do we plan to add this to WebView at a later date? The usual pattern here would be to introduce an Android API that delegates calls to the Android app developer.

[Garfield Tan]

> Do we plan to add this to WebView at a later date? The usual pattern here would be to introduce an Android API that delegates calls to the Android app developer.

There isn't an active plan for it, but I don't want to exclude the possibility if there is such a request. It is a bit tricky to expose device related APIs because it involves system permission requests (for the embedding Android apps) and device enumerations/selections. It is unclear how much WebView should do on the app's behalf vs how much they need to do by themselves. I'd argue we should learn from real requests before jumping on any decisions.

I suppose we should tackle WebUSB and Web Bluetooth first because none of them are available to WebView, there are requests (1, 2) and they have been stably released on Clank for some time already. We can set up a paradigm on how to expose device Web APIs to WebView.

On Fri, Apr 25, 2025 at 2:48 AM Donald Bump <donald...@gmail.com> wrote:

--
You received this message because you are subscribed to the Google Groups "blink-dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+...@chromium.org.
To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/ee0acc10-ffd8-4afa-9062-206834274889n%40chromium.org.

[Alex Russell]

LGTM1; exciting to see this getting filled in!

To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+unsubscribe@chromium.org.

[Garfield Tan]

Thanks.

I need to say that the connected/disconnected events and SerialPort.connected property can't be fully supported on Android over Bluetooth yet due to lack of system support, so this launch request is a catch up to the original Web Serial spec before the connected state was launched.

The connected events and property can either be launched when Android has wired serial port support, or when Android adds the full connected support to Bluetooth.

To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+...@chromium.org.

[Chris Harrelson]

Hi, two questions about this intent:

* Is this just extending existing support on desktop platforms for this feature to Android?

* Are there any API shape changes to support serial over Bluetooth, or is it handled entirely by the UA?

To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAHOF2tMJn2U7EUM1UFqrE_a%3DczS5oLRh%2BCOLp5sVw%2BkW6iys2Q%40mail.gmail.com.

[Garfield Tan]

> * Is this just extending existing support on desktop platforms for this feature to Android?

Yes.

> * Are there any API shape changes to support serial over Bluetooth, or is it handled entirely by the UA?

No changes to any API spec. The UA handles the platform differences.

[Chris Harrelson]

Thanks!

LGTM2

To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAHOF2tO6xrY28ALe5u-UHRiLUOGPG8HYznUKCcFqAgP5ofH0Gg%40mail.gmail.com.

[Yoav Weiss (@Shopify)]

LGTM3

To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOMQ%2Bw8EiXnvXm%3Dm6T44TxOzWP%3DQJGuWMAHNXoL1Y%3D%3DWzOLaXQ%40mail.gmail.com.