Read content from the screen using a syntesized voice and control how it should be read (e.g. language, pitch and volume.)

Find out the current light level or illuminance of the ambient light around the user's device.

The USB interface of the WebUSB API provides attributes and methods for finding and connecting USB devices from a web page.

The Notifications API allows web pages to control the display of system notifications to the end user. These are outside the top-level browsing context viewport, so therefore can be displayed even when the user has switched tabs or moved to a different app. The API is designed to be compatible with existing notification systems, across different platforms.

Play audio, add effects to audio, create audio visualizations, apply spatial effects (such as panning) and much more.

Control how animations are presented and created on the fly - great for allowing the user to adjust animation settings for accessibility.

Provide physical feedback to the user by causing the device to shake.

Change and manipulate the browser URL.

Interpret finger (or stylus) activity on touch screens or trackpads.

Prevent devices from dimming or locking the screen when an application needs to keep running.

The Push API gives web applications the ability to receive messages pushed to them from a server, whether or not the web app is in the foreground, or even currently loaded. This lets developers deliver asynchronous notifications and updates to users that opt in, resulting in better engagement with timely new content.

Add support for styluses and other types of user pointing/input deviced besides a mouse, including detecting of tilt.

The Picture-in-Picture API allow websites to create a floating video window always on top of other windows so that users may continue consuming media while they interact with other content sites, or applications on their device.

Find out when a user has a browser tab focused, or has switched to another tab

HTML Drag and Drop interfaces enable applications to use drag-and-drop features in browsers.

The Gamepad API is a way for developers to access and respond to signals from gamepads and other game controllers in a simple, consistent way. It contains three interfaces, two events and one specialist function, to respond to gamepads being connected and disconnected, and to access other information about the gamepads themselves, and what buttons and other controls are currently being pressed.

The Fullscreen API adds methods to present a specific Element (and its descendants) in full-screen mode, and to exit full-screen mode once it is no longer needed. This makes it possible to present desired content—such as an online game—using the user's entire screen, removing all browser user interface elements and other applications from the screen until full-screen mode is shut off.

The Clipboard API provides the ability to respond to clipboard commands (cut, copy, and paste) as well as to asynchronously read from and write to the system clipboard. Access to the contents of the clipboard is gated behind the Permissions API: The clipboard-write permission is granted automatically to pages when they are in the active tab. The clipboard-read permission must be requested, which you can do by trying to read data from the clipboard.