What is WebTransport?

PubNub Guide - What is WebTransport technology

What is WebTransport?

WebTransport is a new web API standard (communication protocol) designed to provide low-latency, bidirectional communication between web applications and servers. It's intended to replace or supplement existing technologies like Long Polling, WebSockets, XMLHttpRequest, and Fetch. WebTransport networking tech is being developed to address the limitations of older technologies and to better support use cases like multiplayer gaming, real-time collaboration, and other applications requiring high-performance communication.

WebTransportintroduces new transport layer protocol- the QUIC transport protocol- specifically designed for real-time apps. This protocol provides several advantages over traditional protocols like TCP.

One of the key benefits of WebTransport is its improved scalability. The QUIC protocol allows for multiplexing, meaning multiple data streams can be sent over a single connection. This eliminates the overhead of establishing multiple connections, reducing latency and improving software efficiency.

WebTransport also offers enhanced security features with security mechanisms of QUIC, including encryption and authentication. Provides high confidentiality and integrity of data transmitted between clients and servers. This helps protect against common security threats, such as eavesdropping and tampering.

The WebTransport API offers crucial features like flow control, prioritization, and reliable delivery, enabling developers to enhance performance and user experience in real-time apps.

What types of WebTransport services are available?

Several web transport services are available for developers building real-time chat and messaging applications. These services provide a scalable and secure platform for transmitting data over the web. Here are some of the commonly used web transport services:

WebSockets is a bidirectional communication protocol that enables real-time communication between clients and servers. Allowing full-duplex communication, meaning data can be sent and received simultaneously. WebSocket provides a persistent connection, reducing the latency and overhead associated with HTTP polling.

WebRTC (Web Real-Time Communication): is a free, open-source project that enables real-time communication between web browsers and mobile applications. It supports peer-to-peer communication for audio, video, and data transfer. WebRTC can be used for various applications, including video conferencing, voice calling, and live streaming.

Server-Sent Events (SSE): is a unidirectional communication protocol that allows servers to push data to clients over HTTP. Unlike WebSocket, SSE only supports server-initiated communication, where the server sends data to the client without client requests. It is useful for scenarios where real-time updates are needed, such as stock tickers, social media feeds, or news updates.

HTTP/2 server push : allows the server to proactively push resources to the client without waiting for the client to request them. This can send real-time updates or pre-load resources the server predicts the client will need.

What are the benefits of using WebTransport?

Here are some of the key advantages of using WebTransport communication protocol:

  1. Low Latency: WebTransport provides a more efficient transport protocol than traditional techniques like WebSockets. It reduces latency by leveraging advanced congestion control algorithms and improving the overall responsiveness of real-time communications.

  2. Multiplexing and stream prioritization capabilities of WebTransport allows developers to establish multiple logical connections within a single transport. This enables efficient data transfer and reduces the overhead of establishing new connections.

  3. Scalability: With support for multiplexing, WebTransport can handle a larger number of concurrent connections without compromising performance. This scalability makes it an ideal choice for applications with high user engagement or heavy traffic volumes, ensuring a seamless experience for users.

  4. Flexibility: WebTransport supports both reliable and unreliable transport protocols. This versatility facilitates diverse real-time communication patterns like voice/video calling, messaging, and collaborative document editing.

  5. Security: WebTransport use modern security mechanisms like Transport Layer Security (TLS) to encrypt the data exchanged between the client and serve. This makes it a reliable choice for applications that handle sensitive user data.

Are there any risks associated with WebTransport?

Yes, there are some risks associated with WebTransport. Here are a few:

  • Compatibility Issues: Since WebTransport is still an evolving technology and may not be supported by all browsers and platforms, compatibility issues can arise for users accessing your application if they use older or less commonly used browsers. Testing and ensuring compatibility across different platforms is essential to provide a seamless experience for all users.

  • Performance Impact: While WebTransport aims to provide efficient and low-latency communication, improper implementation or large amounts of data transfer can impact the performance of your application.

  • Complexity: WebTransport introduces new concepts and APIs that may be unfamiliar to developers (e.g., the Streams API). This learning curve can make the development process more complex and time-consuming.

  • Dependency on Third-Party Providers: Implementing WebTransport often involves relying on third-party providers or services, such as Content Delivery Networks (CDNs) or cloud hosting platforms. Any issues or downtime with these providers can affect the availability and performance of your WebTransport-enabled application.

How reliable is WebTransport?

Even though WebTransport is a relatively new technology, several factors indicate its potential reliability.

Firstly, WebTransport is built on top of the reliable User Datagram Protocol (UDP), ensuring that data packets are delivered correctly and without loss. UDP has been widely used in real-time applications such as video streaming and online gaming, and its reliability has been proven over time.

Additionally, WebTransport incorporates several mechanisms to enhance reliability. It uses forward error correction (FEC) to recover lost packets and reduce the impact of packet loss. It also supports congestion control algorithms to avoid network jams and maintain a stable and reliable connection.

Furthermore, WebTransport uses the existing web infrastructure, including HTTPS, which provides secure and encrypted communication. This ensures the integrity and confidentiality of the transmitted data, adding an extra layer of reliability.

However, it is essential to note that the reliability of WebTransport also depends on the underlying network specifications and the application's implementation. Factors such as network latency, bandwidth, and server load can affect the overall reliability of the communication.

How do I implement WebTransport?

Implementing WebTransport requires a few steps to ensure a successful integration into your real-time chat and messaging applications. Here’s how to start:

  1. Check browser support: Before implementing WebTransport, verify that the target browsers support this technology. Currently, WebTransport is supported in Chromium-based browsers such as Firefox, Google Chrome, and Microsoft Edge. (As of this writing, it’s not available on Safari). You can check the current browser compatibility status on or other similar resources.

  2. Set up a WebTransport server: To implement WebTransport, you will need a server that supports the WebTransport protocol. Various server implementations are available:

    • webtransport: This is a JavaScript library developed by the W3C WebTransport Working Group. It provides a high-level API for establishing WebTransport connections and sending/receiving data over the connection.

    • quiche: This is a Rust library developed by CloudFlare. It is a general-purpose QUIC library that can also implement WebTransport. Quiche provides low-level control over the QUIC protocol and allows for fine-grained customization.

    • aioquic: This Python library provides a high-level API for implementing QUIC and WebTransport. It is built on the quiche library and easily integrates WebTransport into your Python applications.

    • libwebsockets: This C library provides a lightweight and efficient way to implement WebTransport. It supports client- and server-side implementations and offers a flexible API for sending and receiving data over WebTransport connections. Alternatively, you can use other server implementations like Warp. Choose the server implementation that best suits your needs and follow the documentation to set it up.

  3. Establish a WebTransport connection: Once you have set up the server, you can establish a WebTransport connection from your client-side application. This typically involves creating a WebTransport session object and specifying the server's URL. You can use JavaScript APIs, such as the WebTransport API, to handle the connection establishment and data transmission.

  4. Handle data transmission: With a WebTransport connection established, you can start transmitting data between the client and the server. This can include sending and receiving chat messages, real-time updates, or other relevant data. Use the WebTransport API to handle data streams, sending and receiving data reliably and efficiently.

  5. Test and optimize: After implementing WebTransport in your application, it is crucial to test and optimize its performance thoroughly. This includes testing the reliability and efficiency of data transmission, handling different network conditions, and analyzing any potential bottlenecks or performance issues. Conduct stress tests, simulate various network scenarios, and monitor the application's performance to identify and address any problems.

  6. Consider security measures: As WebTransport involves transmitting data over the internet, it is essential to consider security measures to protect the integrity and confidentiality of the data. Implement HTTPS encryption to ensure secure communication between the client and the server. Additionally, consider implementing authentication and authorization mechanisms to restrict access to the WebTransport connection and prevent unauthorized usage.

  7. Monitor and analyze: Once your WebTransport-based application is live, it is crucial to monitor and analyze its performance continuously. Monitor network conditions, server load, and user feedback to identify potential issues and make necessary optimizations. Analyze the data transmission efficiency, latency, and overall reliability to ensure the application meets your performance requirements.

WebTransport vs. HTTP/3

WebTransport and HTTP/3 are essential technologies revolutionizing how real-time chat and messaging applications are built. In this section, we will explore the benefits and features of these technologies and why developers should consider using them in their applications.

In short, WebTransport is built on top of HTTP/3.

WebTransport is a newer protocol developed by the W3C WebTransport Working Group and aims to provide web applications with a low-latency, bidirectional, and secure transport layer.

HTTP/3 is the latest version of the Hypertext Transfer Protocol (HTTP) standardized by the Internet Engineering Task Force (IETF). It is built on top of the QUIC transport protocol, designed to overcome TCP connections’ limitations.

Now, let's dive into the benefits of using WebTransport and HTTP/3 in real-time chat and messaging applications:

  1. Low latency: WebTransport and HTTP/3 are designed to minimize latency by reducing the number of round trips required for each request. This is particularly important for real-time chat and messaging applications, where low latency is crucial for delivering real-time messages. By establishing a persistent connection and supporting multiplexing, WebTransport and HTTP/3 significantly reduce the time it takes for a request to reach the server and receive the response. This ensures that messages are delivered quickly, creating a seamless and responsive user experience.

  2. Improved performance: The persistent connection and multiplexing capabilities of WebTransport and HTTP/3 also contribute to improved overall performance of real-time chat and messaging applications. With fewer round trips and the ability to send multiple requests concurrently, these technologies enable faster data transmission and more efficient network utilization. This means that applications can handle more concurrent users and deliver messages in real time without compromising performance.

  3. Scalability: Real-time chat and messaging applications often need to handle many concurrent users. WebTransport and HTTP/3 are designed to scale efficiently, allowing applications to take high loads without significantly impacting performance. The persistent connection and multiplexing features enable efficient resource utilization, reducing the need for additional server resources to handle concurrent requests. This makes WebTransport and HTTP/3 ideal for building scalable chat and messaging applications.

  4. Security: Security is critical to any chat and messaging application. WebTransport and HTTP/3 prioritize security by providing secure transport layers for web applications. WebTransport uses the existing security mechanisms of the web platform, such as TLS, to ensure secure communication between the client and the server. HTTP/3 also incorporates security measures such as encryption and server authentication to protect data transmission and prevent unauthorized access. By using WebTransport and HTTP/3, developers can build real-time chat and messaging applications that prioritize the security and privacy of user data.

  5. Compatibility with existing infrastructure: WebTransport and HTTP/3 are designed to be backward compatible with existing web infrastructure. This means that developers can easily integrate these technologies into their existing applications without significant changes to their codebase or infrastructure. By leveraging the existing infrastructure, developers can quickly adopt WebTransport and HTTP/3 and take advantage of their benefits without disrupting their current systems.

  6. Elimination of Head-of-line blocking: Head-of-line blocking occurs when a request is blocked by previous requests that are still in progress. In the context of real-time chat and messaging applications, this means that if one message is delayed or blocked, it can prevent subsequent messages from being delivered in a timely manner.

    WebTransport solves this problem by introducing a multiplexing feature that allows multiple requests to be sent concurrently over a single connection. This means that even if one request is delayed or blocked, other requests can still be processed and delivered. As a result, messages can be sent and received in real time without being affected by delays or blocks.

    HTTP/3 reduces the impact of head-of-line blocking through its use of QUIC, which allows for independent packet transmission, reducing the delay caused by lost or delayed packets.

PubNub and WebTransport

PubNub supports WebTransport. PubNub is a real-time messaging and chat platform that provides developers with the tools and infrastructure to build scalable and secure two-way chat applications.

WebTransport also works with Real-Time Text (RTT), and its ability to reduce latency and improve performance directly impacts the Round Trip Time (RTT) in real-time chat and messaging applications. Using the QUIC transport protocol and its multiplexing feature, WebTransport allows concurrently processing multiple requests, optimizing message delivery, and maintaining a responsive chat experience for users, regardless of the RTT. Testing and monitoring the application using WebTransport is essential to evaluate its impact on RTT and overall performance, as specific improvements will depend on network conditions and infrastructure setup.

By integrating PubNub with WebTransport, developers can take advantage of the benefits offered by both technologies. Also, PubNub has no concurrency limits, so you’ll never be financially penalized for your app’s growth.

Scalability: Real-time chat and messaging applications often need to handle many concurrent users. WebTransport and HTTP/3 are designed to scale efficiently, allowing applications to take high loads without significantly impacting performance. The persistent connection and multiplexing features enable efficient resource utilization, reducing the need for additional server resources to handle concurrent requests. This makes PubNub with WebTransport an excellent choice for developers looking to build scalable chat apps.

Reliability: The QUIC transport protocol used by HTTP/3 offers built-in error correction and congestion control mechanisms, ensuring that data is transmitted reliably even in challenging network conditions. Messages are less likely to be lost or delayed, providing a more reliable and seamless user experience.

Security: WebTransport and HTTP/3 provide enhanced security features compared to their predecessors. HTTP/3 uses encryption by default, ensuring that data transmitted between the client and the server is protected from eavesdropping and tampering. This helps to prevent unauthorized access to sensitive user information and ensures the privacy of communications. PubNub employs enterprise-grade security measures to protect our systems, data, and product(s), which keeps our customers secure.

Compatibility: PubNub with WebTransport is compatible with a wide range of platforms, devices, and browsers, making it easy for developers to build cross-platform chat applications. PubNub is programming language-agnostic, too.

PubNub’s real-time data APIs allow users to develop robust, event-driven applications to facilitate real-time communication across all devices, regardless of the specific use case. PubNub offers a variety of SDKs, such as a JavaScript SDK for web applications and a C-Core SDK for IoT applications, to ensure seamless integration with the chosen device.

With PubNub, you don’t have to worry about selecting a suitable alternative or the underlying complexities of implementing a real-time solution. Sign up for a free trial and get up to 200 MAUs or 1M total transactions per month included.