What is WebRTC?

What is WebRTC?

WebRTC, short for Web Real-Time Communication, is an open-source project that enables real-time communication capabilities directly within web browsers and mobile applications. It provides APIs and protocols, allowing developers to build applications with real-time audio, video, and data streaming capabilities.

WebRTC allows users to establish peer-to-peer connections at its core without needing plugins or third-party software. It utilizes a combination of JavaScript APIs, HTML5, and the Real-Time Protocol (RTP) to enable audio and video communication between browsers.

One of the key advantages of WebRTC is its ability to work across different platforms and devices, including desktops, smartphones, and tablets. This cross-platform compatibility makes it a versatile solution for developers looking to build real-time chat and messaging applications that can reach a wide audience.

WebRTC also offers built-in encryption and security mechanisms, which ensure that communications are protected and private. Additionally, WebRTC provides efficient bandwidth utilization and adaptive streaming, allowing for high-quality audio and video even under challenging network conditions.

Another notable feature of WebRTC is its support for data channels. These channels enable the transfer of arbitrary data between peers, which can be useful for sharing files, collaborating on documents, or building interactive applications.

From a development perspective, WebRTC provides a set of JavaScript APIs encapsulating the underlying complexities of establishing and managing real-time connections. Developers can focus on building their applications rather than dealing with the intricacies of network protocols and codecs.

One of the key components of WebRTC is the getUserMedia API, which allows developers to access a user's camera and microphone directly from the browser. This API enables the creation of video conferencing and streaming applications and applications that require audio input or output.

WebRTC also includes the RTCPeerConnection API, which handles the signaling and establishment of peer-to-peer connections. This API provides methods for adding and removing audio, video, and data streams and controlling their quality and bandwidth usage.

How does WebRTC work?

At its core, WebRTC utilizes a combination of technologies to establish a peer-to-peer connection between two devices. These technologies include the Session Description Protocol (SDP), Interactive Connectivity Establishment (ICE), and the Real-Time Transport Protocol (RTP).

The process of establishing a WebRTC connection involves several steps. First, the devices must exchange information about their network addresses and capabilities. This is done using the SDP, which describes the media streams, codecs, and network parameters.

Once the SDP information is exchanged, the devices use ICE to discover the most efficient way to connect. ICE considers various factors such as network type, firewall configurations, and available transport protocols to determine the best path for the connection.

After establishing the connection, the devices use RTP to transmit real-time media streams, such as audio and video. RTP provides mechanisms for packetization, sequencing, and time synchronization of the media data. It also supports encryption and quality-of-service controls.

WebRTC also incorporates security measures to protect the privacy and integrity of the communication. It supports encryption using Datagram Transport Layer Security (DTLS) to ensure a secure connection. This prevents malicious actors from intercepting or tampering with the data being transmitted.

Why use WebRTC?

1. Real-time communication: WebRTC allows real-time communication between web browsers and mobile applications. This is essential for video conferencing, chat, and online gaming applications, where low latency and high-quality audio and video are crucial.

2. Peer-to-peer connection: WebRTC establishes a direct peer-to-peer connection between devices, bypassing the need for a centralized server. This reduces latency and increases scalability by distributing the load across multiple devices.

3. Cross-platform compatibility: WebRTC is supported by major web browsers, including Chrome, Firefox, Safari, and Edge. It also has native support on iOS and Android devices. This cross-platform compatibility allows developers to build applications that work seamlessly across different devices and operating systems.

4. Easy to develop: WebRTC provides a set of JavaScript APIs that simplify the development process. Developers can use these APIs to access device media streams, handle peer connections, and transmit real-time data. Additionally, numerous frameworks and libraries provide higher-level abstractions and simplify common tasks.

5. Secure communication: WebRTC incorporates security measures to protect the privacy and integrity of the communication. Using DTLS encryption, WebRTC ensures that the transmitted data is secure and cannot be intercepted or tampered with by malicious actors.

What types of applications can be built using WebRTC?

WebRTC provides developers with a set of APIs that can be used to build a wide range of applications. Here are some use cases for WebRTC:

Best practices for building WebRTC applications:

  1. Optimize network conditions: WebRTC performance heavily relies on network conditions. Optimizing network conditions is important to ensure a smooth user experience. This can be done by reducing latency, increasing bandwidth, and minimizing packet loss. Developers should use congestion control, adaptive bitrate streaming, and error correction techniques to optimize network conditions.

  2. Implement quality-of-service controls: WebRTC provides features to control the quality of communication. Developers should use these features to ensure the audio and video quality meets the desired standards. This can include setting video resolution, frame rate, and audio bitrate.

  3. Handle network disruptions gracefully: Network disruptions can occur for reasons such as signal loss, network congestion, or device mobility. Developers should implement mechanisms to handle such disruptions gracefully. This can include techniques such as buffering, retransmission, and adaptive streaming to maintain a continuous and uninterrupted communication experience.

  4. Secure the application: While WebRTC incorporates security measures, developers should also take additional steps to secure their applications. This can include implementing authentication mechanisms, encrypting sensitive data, and using secure protocols for data transmission. Developers should also regularly update their applications to patch any security vulnerabilities.

  5. Test and monitor the application: Testing and monitoring are crucial for ensuring the performance and reliability of WebRTC applications. Developers should conduct thorough testing to identify any issues with the application, such as compatibility issues, performance bottlenecks, or security vulnerabilities. They should also monitor the application in real-time to detect any issues and take necessary actions to resolve them.

What web browsers support WebRTC?

WebRTC is supported by a wide range of modern web browsers, making it a versatile and accessible choice for developers. Here are the major web browsers that support WebRTC:

  1. Google Chrome: Chrome has been a strong supporter of WebRTC since its early days and has robust support for its APIs. It is recommended to use Chrome for testing and development purposes due to its extensive debugging tools and frequent updates.

  2. Mozilla Firefox: Firefox is another browser with excellent WebRTC support. Mozilla has been actively developing WebRTC and has implemented several features and improvements to enhance the user experience.

  3. Safari: Safari, the default browser on Apple devices, has also supported WebRTC. However, it is important to note that Safari's implementation may have some limitations compared to Chrome and Firefox, so additional testing and fallback mechanisms may be necessary for cross-browser compatibility.

  4. Microsoft Edge: Edge, the successor to Internet Explorer, has added WebRTC support since transitioning to Chromium-based architecture. While earlier versions of Internet Explorer do not support WebRTC, Edge provides a modern and compatible environment for WebRTC applications.

  5. Opera: Opera also supports WebRTC and provides a reliable platform for building real-time communication applications. While it may not have the same level of popularity as Chrome or Firefox, Opera's support for WebRTC is still robust and can be a viable choice for developers.

It is important to note that while these browsers support WebRTC, there may be slight variations in their implementations. Therefore, testing your application across different browsers is recommended to ensure cross-browser compatibility. Additionally, it is always a good idea to have fallback mechanisms in place to handle scenarios where WebRTC is not supported or if there are limitations in certain browsers.

What are the challenges of using WebRTC?

While WebRTC offers exciting possibilities for developers building real-time chat and messaging applications, it also comes with its fair share of challenges. Let's dive into some of the major challenges:

Browser Compatibility:

One of the primary challenges of using WebRTC is ensuring compatibility across different web browsers. While major browsers like Chrome, Firefox, and Safari support WebRTC, they may have different implementations and versions, leading to compatibility issues. Developers should thoroughly test their applications on various browsers to ensure a consistent user experience.

Network and Firewall Traversal:

WebRTC utilizes peer-to-peer (P2P) connections for real-time communication, allowing direct data transfer between users. However, this can be challenging when users are behind restrictive firewalls or Network Address Translation (NAT) devices. Establishing P2P connections in such scenarios requires additional techniques like STUN (Session Traversal Utilities for NAT) and TURN (Traversal Using Relays around NAT) servers.

Security and Privacy:

Real-time communication applications often handle sensitive information, making security and privacy crucial. WebRTC supports encryption for media streams, ensuring secure communication. However, developers must ensure proper implementation of security measures and stay updated with the latest encryption standards to mitigate potential vulnerabilities. Additionally, handling user privacy and consent for data sharing is another challenge, as it requires careful consideration and adherence to privacy regulations.


Building a scalable real-time chat or messaging application with WebRTC can be challenging. As the number of users and data transfers increases, the server infrastructure must handle the load efficiently. Developers must design and deploy a robust backend infrastructure to handle high traffic and provide seamless real-time communication.

Performance Optimization:

Real-time communication applications need to deliver a smooth and lag-free experience to users. Developers should optimize their application's performance to minimize latency and ensure smooth audio and video streams. This can involve techniques like bandwidth estimation, adaptive bitrate streaming, and efficient handling of network fluctuations.

Debugging and Troubleshooting:

Debugging and troubleshooting issues in WebRTC applications can be complex. Developers need to deeply understand the WebRTC protocol and its internals to identify and resolve issues effectively. Logging and debugging tools specific to WebRTC (discussed next) can help streamline this process.

What tools are available to help developers debug WebRTC applications?

Developing WebRTC applications can be challenging, and when issues arise, it's essential to have the right tools for debugging and troubleshooting. Fortunately, there are several tools available to assist developers in this process. Let's explore some of them:

  1. WebRTC-internals:

    This built-in tool in Google Chrome provides a wealth of information about WebRTC sessions, including detailed logs, network statistics, and media stream details. Developers can access this powerful debugging to “chrome://webrtc-internals" in the browser's address bar.

  2. Browser Developer Tools:

    The developer tools in modern web browsers, such as Chrome DevTools or Firefox Developer Tools, are invaluable for debugging WebRTC applications. They allow developers to inspect network requests, examine console logs, monitor WebSocket connections, and analyze various aspects of the application's behavior.

  3. Wireshark:

    Wireshark is a widely used network protocol analyzer that captures, analyzes, and interprets network traffic. It helps developers gain deeper insights into the underlying network protocols and identify potential issues with WebRTC connections.

  4. AppRTC:

    AppRTC is an open-source WebRTC application developed by Google. It serves as a reference implementation and can be used as a testing tool for WebRTC applications. Developers can use AppRTC to simulate real-time communication scenarios, helping to identify and resolve issues.

  5. TestRTC:

    TestRTC is a cloud-based testing and monitoring platform specifically designed for WebRTC applications. It provides real-time monitoring, automated testing, and performance analysis, allowing developers to identify and fix issues before they impact users.

  6. SRT (Secure Reliable Transport):

    SRT is an open-source video streaming protocol that can be used alongside WebRTC to enhance its capabilities. It provides error correction and congestion control mechanisms, improving the overall reliability and stability of WebRTC connections. SRT can be a valuable tool for diagnosing and resolving packet loss, latency, and network congestion issues.

  7. Third-party libraries and frameworks:

    There are numerous third-party libraries and frameworks available that can assist developers in debugging WebRTC applications. Examples include SimpleWebRTC, PeerJS, and Janus Gateway. These libraries offer additional functionality, debugging tools, and documentation to support developers' WebRTC development efforts.

What audio and video codecs are used in WebRTC?

WebRTC supports audio and video communication by utilizing specific codecs, specifically:

Audio Codecs:

Video Codecs:

It is important to note that the availability of these codecs may vary depending on the browser and device used. Developers should consider the compatibility of codecs when building WebRTC applications to ensure a seamless experience for users across different platforms.

How does the WebRTC API work?

The WebRTC API (Application Programming Interface) is a collection of JavaScript APIs that allows developers to build real-time communication applications directly in web browsers. It provides the necessary functionality for establishing peer-to-peer connections, transferring audio and video streams, and exchanging data between web browsers.

Here is a high-level overview of how the WebRTC API works:

  1. User Media: The getUserMedia API is used to access the user's media devices, such as the camera and microphone. This allows the application to capture audio and video streams from the user's device.

  2. Signaling: Before establishing a WebRTC connection, the two communicating peers need to exchange information about their network addresses and media capabilities. This is done through a signaling server, which can be implemented using various protocols like WebSocket or HTTP. The signaling server acts as a middleman to facilitate the connection setup.

  3. Peer Connection: Once the signaling process is complete, the WebRTC API creates a peer connection object for each communicating peer. The peer connection handles the negotiation and establishment of the connection. It manages the transmission and reception of audio and video streams and handles any necessary encryption and security measures.

  4. ICE Candidates: The Interactive Connectivity Establishment (ICE) framework establishes a connection between peers, even if they are behind firewalls or using different network protocols. ICE generates a list of network addresses, called ICE candidates, and it uses various techniques like STUN (Session Traversal Utilities for NAT) and TURN (Traversal Using Relays around NAT) to discover the best possible route for communication between peers.

  5. Media Stream: Once the peer connection is established, the WebRTC API handles the transfer of audio and video streams between peers. It uses real-time protocols like RTP (Real-time Transport Protocol) and SRTP (Secure Real-time Transport Protocol) to ensure reliable and secure media data transmission.

  6. Data Channel: Besides audio and video streams, the WebRTC API also supports the exchange of arbitrary data between peers. This is done through a data channel, which provides a reliable, ordered, and secure communication channel for sending messages or data packets.

  7. Security: WebRTC provides built-in security mechanisms to protect the privacy and integrity of the communication. It uses encryption algorithms like DTLS (Datagram Transport Layer Security) and SRTP for secure media data transmission. It also supports certificate-based authentication to ensure that only trusted peers can establish a connection.

What are some WebRTC Alternatives?

Some alternatives to WebRTC for real-time communication include:

  1. SIP (Session Initiation Protocol): SIP is a signaling protocol for initiating, modifying, and terminating real-time sessions involving video, voice, messaging, and other communications applications and services. It is widely used in VoIP (Voice over Internet Protocol) systems.

  2. XMPP (Extensible Messaging and Presence Protocol): XMPP is an open-standard communication protocol for instant messaging, presence information, and contact list management. It can be extended to support real-time voice and video communication as well.

  3. MQTT (Message Queuing Telemetry Transport): MQTT is a publish-subscribe messaging protocol commonly used in IoT applications. It is designed to be lightweight and efficient, making it suitable for devices with limited processing power and bandwidth. While WebRTC and MQTT are not directly related, using them together in certain scenarios is possible. For example, suppose you are building a real-time chat application that requires audio/video communication and messaging capabilities. In that case, you can use WebRTC for audio/video streaming and MQTT for messaging.

  4. WebSockets: Although WebSockets are often used with WebRTC, they can also be used as an alternative for real-time communication. WebSocket is a communication protocol that provides full-duplex communication channels over a single TCP connection. It allows for real-time, bi-directional communication between clients and servers.

  5. Jingle: Jingle is an extension to the XMPP protocol that adds multimedia session initiation capabilities, including audio, video, and file transfer. It is commonly used in voice and video chat applications.

WebRTC vs. WebSockets

WebRTC and WebSockets are both technologies that enable real-time communication on the web, but they serve different purposes and work in different ways.

WebRTC is a collection of APIs and protocols that allow for peer-to-peer communication between web browsers. It enables direct real-time audio, video, and data transfer between users without intermediate servers. WebRTC uses a combination of signaling, NAT traversal, and media streaming to establish and maintain direct connections between browsers.

On the other hand, WebSockets is a communication protocol that provides full-duplex communication between a client and a server over a single, long-lived connection. It allows for real-time, bidirectional communication by keeping the connection open and allowing the client and the server to send messages at any time.

So, how do WebRTC and WebSockets work together? While WebRTC enables direct peer-to-peer communication, it still requires an initial connection setup and signaling to establish the direct communication channel between peers. This is where WebSockets can be used.

WebSockets can be used as the signaling channel for WebRTC. When a user wants to establish a WebRTC connection with another user, they can use a WebSocket connection to exchange the necessary signaling messages. These signaling messages contain information about the users, session descriptions, ICE candidates, and other details required to establish a direct peer-to-peer connection.

Once the WebRTC connection is established through the WebSockets signaling process, the actual media and data transfer can occur directly between the browsers using WebRTC's peer-to-peer capabilities.

Benefits of Using WebRTC and WebSockets Together

By combining WebRTC and WebSockets, developers can leverage both technologies' strengths to build powerful real-time applications. Here are some benefits of using them together:

Challenges of Using WebRTC and WebSockets Together

Best Practices for Using WebRTC and WebSockets Together

To overcome these challenges and make the most out of using WebRTC and WebSockets together, developers should follow these best practices:


WebRTC and MQTT are popular technologies in real-time communication and messaging applications. While they both serve a similar purpose, there are some key differences between them that developers need to consider when choosing the right technology for their applications, which we discuss below.




Use Cases:

What is the future of WebRTC?

Since its introduction, WebRTC has gained significant traction and has become a crucial technology for various applications such as video conferencing, online gaming, customer support, and more.

Looking ahead, the future of WebRTC appears promising and filled with exciting possibilities. Here are some key trends that are likely to shape its development and adoption in the coming years:

Enhanced Browser Support: While major web browsers, including Chrome, Firefox, and Safari, already support WebRTC, we can expect even broader adoption and improved compatibility across different platforms. As browsers refine their implementations, developers will have more flexibility in building feature-rich applications.

Increased Mobile Usage: Mobile devices have become an indispensable part of our lives, and the demand for mobile real-time communication is growing rapidly. With the proliferation of 5G networks and advancements in mobile hardware, WebRTC is expected to play a significant role in delivering seamless real-time experiences on smartphones and tablets.

Integration with IoT: The Internet of Things (IoT) is expanding rapidly, connecting various devices and enabling smart homes, cities, and industries. WebRTC can leverage its real-time capabilities to bridge the gap between IoT devices and web applications. It opens up possibilities for remote monitoring, control, and collaboration across a wide range of IoT use cases.

Collaboration and Team Communication: As remote work is now a way of life for many of us, the need for effective collaboration and team communication tools continues to grow. WebRTC provides the foundation for real-time audio and video communication, making it an ideal solution for remote teams.

Augmented Reality and Virtual Reality: The immersive experience of augmented reality (AR) and virtual reality (VR) has gained immense popularity in recent years. WebRTC enhances AR and VR applications by enabling real-time communication between users, allowing them to interact and collaborate in virtual environments. This opens up new possibilities in gaming, training, remote assistance, and more.

Security and Privacy: With the increasing importance of data security and privacy, WebRTC will continue to evolve to address these concerns. Efforts are being made to improve encryption standards and implement secure protocols, ensuring user information and communication remain protected. Developers building WebRTC applications should prioritize security measures to maintain user trust.

Scalability and Performance: As WebRTC applications become more mainstream, scalability and performance will be key considerations. The ability to handle many simultaneous connections and deliver high-quality audio and video streams will be crucial for the success of real-time applications. Developers must optimize their applications and leverage advanced techniques such as adaptive bitrate streaming to ensure a smooth and reliable user experience.

How does PubNub work with WebRTC?

PubNub is a real-time messaging and data streaming platform that can work with WebRTC to enhance its capabilities. PubNub provides a global network infrastructure that allows developers to build and scale real-time applications quickly and easily.

When integrating PubNub with WebRTC, developers can leverage PubNub's features and functionalities to enhance their real-time communication applications. Here's how PubNub works with WebRTC:

  1. Signaling: WebRTC requires a signaling mechanism to establish and control peer communication. PubNub can be used as a signaling channel to exchange session metadata, initiate connections, and coordinate the establishment of WebRTC peer connections.

  2. Presence and Channel Management: PubNub provides presence functionality, allowing developers to track users' online/offline status in real time. This can be useful for building features such as user availability indicators or building chat applications with online/offline presence awareness. PubNub also allows developers to create channels to organize and manage peer communication.

  3. Message Broadcasting: PubNub's publish/subscribe model enables developers to broadcast messages to multiple subscribers in real time. This can send chat messages, notifications, or other data types between peers. By combining PubNub's message broadcasting capabilities with WebRTC, developers can create real-time chat applications that seamlessly integrate with WebRTC's audio and video communication.

  4. Data Synchronization: PubNub's data streaming capabilities can synchronize data across devices and ensure all connected peers can access the latest information. This is particularly useful for collaborative applications where multiple users need to interact with the same data in real time. By integrating PubNub with WebRTC, developers can easily synchronize and update data across all connected peers, enabling seamless collaboration.

  5. Security and Access Control: PubNub offers various security features to ensure the confidentiality and integrity of data transmitted over the network. Developers can implement access control rules, encrypt data, and authenticate users to protect their real-time communication applications. By leveraging PubNub's security features, developers can build secure and reliable real-time applications with WebRTC.

In addition to these features, PubNub provides functionalities such as message filtering, history storage, playback, and advanced analytics. These capabilities can further enhance the functionality and performance of real-time applications built with WebRTC.

Are you curious about how PubNub fits into your WebRTC project? Our experts are standing by to chat about your products. Or, if kicking the tires is more your speed, sign up for a free trial or check out our GitHub.