Opposed features
The following features have received negative standards positions from at least one browser vendor. They're very unlikely to ever become Baseline in their current forms.
-
Accelerometer
Limited availabilityThe
Accelerometer,LinearAccelerationSensorandGravitySensorAPIs read the acceleration applied to a device in three dimensions, either including the effect of gravity, without its effect, or only its effect, respectively. -
Background sync
Limited availabilityThe background synchronization API registers a service worker callback to run only when the device is no longer offline. You can use this to let users continue using your app while offline and synchronize with a server after reconnecting.
-
CPU compute pressure
Limited availabilityThe
PressureObserverAPI monitors CPU load, allowing you to adjust workloads in response to available computing resources. Also known as the Compute Pressure API. -
Customized built-in elements
Limited availabilityCustomized built-in elements are HTML elements that extend built-in elements using the
isattribute, to add new behaviors that you define.- Chrome 67 Released on 2018-05-29
- Chrome Android 67 Released on 2018-05-31
- Edge 79 Released on 2020-01-15
- Firefox 63 Released on 2018-10-23
- Firefox for Android 63 Released on 2018-10-23
- Safari Not supported Position: oppose
- Safari on iOS Not supported Position: oppose
Baseline availability blocked since January 2020 by Safari (82 months)
-
Form-associated WebMCP attributes
Limited availabilityThe
toolname,tooldescription, andtoolautosubmitHTML form element attributes register actions that can be called by in-browser AI agents or browser extensions. Also known as declarative WebMCP. -
document.modelContext
Limited availabilityThe
document.modelContextAPI registers page actions that can be called by in-browser AI agents or browser extensions. Also known as WebMCP. -
Element capture
Limited availabilityThe
restrictTo()method on screen capture media tracks limits capture to a specific element, excluding content which might occlude the element itself, such as video conferencing controls. -
File system access
Limited availabilityThe
showOpenFilePicker(),showDirectoryPicker(), andshowSaveFilePicker()methods request access to files and directories on the user's device and returns a handle for reading and writing to them. -
Gyroscope
Limited availabilityThe
GyroscopeAPI reads the angular velocity of a device in three dimensions. -
Idle detection
Limited availabilityThe
IdleDetectorAPI is used to notify a webpage of the user's idle, active, and locked state. -
Keyboard lock
Limited availabilityThe
navigator.keyboard.lock()API allows you to capture keys that are normally reserved by the operating system. It can be used to provide an immersive fullscreen experience such as games. -
Keyboard map
Limited availabilityThe
navigator.keyboard.getLayoutMap()API returns a map from key codes to human readable key names. It can be used to describe buttons to the user when using the keyboard as a set of buttons, such as in games. -
LanguageModel
Limited availabilityThe
LanguageModelAPI prompts an on-device language model. Also known as the Prompt API. -
Network Information
Limited availabilityThe
navigator.connectionAPI provides information about the network connection a device is using and fires events when the connection type changes. -
Observable
Limited availabilityThe
when()method on a event target returns anObservableobject, which provides a declarative API for subscribing to and operating on events. It's an alternative toaddEventListener()callbacks. -
Orientation Sensor
Limited availabilityThe
AbsoluteOrientationSensorandRelativeOrientationSensorAPIs describe the physical orientation of a device in three-dimensional space, either in relation to the Earth's coordinate system or in relation to the device's own orientation, respectively. -
Web serial
Limited availabilityThe
navigator.serialAPI communicates with devices over serial ports, such as microcontrollers. -
Summarizer
Limited availabilityThe
SummarizerAPI uses an on-device language model to summarize text. -
Vibration
Limited availabilityThe
navigator.vibrate()method makes a tactile alert, if the device is equipped with a haptic motor. -
Virtual pressure sources
Limited availabilityThe
CreateVirtualPressureSourceWebDriver command creates artificial sources of compute pressure for testing without the need real device sources of compute pressure. -
Web Bluetooth
Limited availabilityThe Web Bluetooth API enables selecting and communicating with nearby Bluetooth devices.
-
Web NFC
Limited availabilityThe
NDEFReaderAPI reads and writes messages to near-field communication (NFC) tags. -
WebHID
Limited availabilityThe WebHID API provides access to Human Interface Devices (HID) that are connected to the user's device.
-
WebUSB
Limited availabilityThe WebUSB API exposes USB compatible devices to web pages.
-
Raw camera access for WebXR
Limited availabilityThe
XRView.cameraproperty provides direct access to pose-synchronized camera images within a WebXR session.