The WebUSB API provides a way to expose non-standard Universal Serial Bus (USB) compatible devices services to the web, to make USB safer and easier to use.
Understanding the WebUSB API
At its core, the WebUSB API is a feature that allows websites running in a web browser to communicate directly with USB devices that are plugged into the user's computer or mobile device. Historically, interaction with USB devices from the web was not possible for security and technical reasons, requiring native applications or specialized browser plugins.
The WebUSB API aims to bridge this gap by:
- Exposing Non-Standard Services: It specifically targets devices that use custom communication protocols, unlike standard device classes such as keyboards, mice, or storage drives, which are typically handled directly by the operating system.
- Improving Safety: By running within the browser's security sandbox, the API provides a more controlled environment for interacting with hardware compared to potentially untrusted native applications. User permission is required before a website can connect to a device.
- Enhancing Ease of Use: It simplifies the process of accessing USB devices from a web application, potentially eliminating the need for users to install drivers or dedicated software.
Key Capabilities
The WebUSB API allows websites to perform operations such as:
- Enumerating available USB devices.
- Connecting to a specific device selected by the user.
- Reading data from and writing data to device endpoints (communication channels).
- Claiming interfaces on the device to take control of specific functions.
- Sending and receiving control transfers for configuration and status requests.
Practical Applications
The ability to interact with non-standard USB devices from the web opens up possibilities for various applications:
- Hardware Interaction: Websites can communicate with custom-built electronics (like Arduino or Raspberry Pi projects connected via USB), industrial equipment, or unique peripherals.
- Firmware Updates: Manufacturers can provide web-based tools for updating device firmware without requiring a standalone application.
- Educational Tools: Interactive tutorials or coding environments in the browser can connect directly to development boards.
- Specialized Peripherals: Web applications can interface with niche devices like lab equipment, point-of-sale devices, or custom sensors.
Benefits of Using WebUSB
| Feature | Description |
|---|---|
| Accessibility | Users can interact with devices directly from a web browser. |
| Reduced Installation | Often eliminates the need to install separate drivers or applications. |
| Enhanced Security | Operates within the browser's security model, requiring explicit user consent. |
| Cross-Platform Potential | Works on any operating system and browser that supports the API. |
| Simplified Development | Provides a standard web interface for interacting with hardware. |
By making it safer and easier to expose non-standard USB device services to the web, the WebUSB API enables a new class of web applications that can directly interface with the physical world through connected hardware.
