Symbl.ai's Web SDK simplifies the process of handling WebSocket connections and managing audio from multiple devices in web applications. The SDK takes care of the bi-directional handshake and network-related issues, allowing developers to focus on core application functionality. With the Web SDK, developers can easily manage multiple WebSocket connections by creating multiple instances of the Symbl() object and handle device changes with automatic device handling mechanism that updates codec and sample rates appropriately. Additionally, the SDK supports a wide range of audio codecs and sample rates, and allows developers to input custom audio streams with only a few lines of code. By using the Web SDK, developers can build applications quickly and efficiently.