Difference Between MQTT vs. WebSocket for IoT

Difference Between MQTT vs. WebSocket for IoT

MQTT is a lightweight publish/subscribe protocol of a network used in web browsers to transfer messages between devices/machines directly. It is ideal for signal transmission and is typically employed in restricted devices with low bandwidth, high latency, or unstable networks. It also allows you to send commands to control actions, publish data, and do various other things. Because IoT applications such as Alexa do not require a web browser to send or receive data, this protocol is appropriate.

On the other hand, WebSocket is a computer communication protocol(CCP) that establishes a two-way channel between a web browser and a server. It operates on a single TCP connection and overcomes HTTP constraints to enable low-latency bidirectional communication. Using MQTT over a Web socket allows you to activate all of MQTT’s functionality, which is utilized for a variety of applications, including:

  • Displaying real-time data
  • Enabling push and alert notifications
  • To examine the current status of devices using messages that have been saved.
  • Simple communication with mobile and web applications

Key Differences of MQTT vs. WebSocket

The following are the primary distinctions between MQTT and WebSocket:

  • MQTT is an abbreviation for MQ Telemetry Transport, the primary protocol for messaging over tiny devices. MQTT and Websockets are two distinct protocols on various tiers, such as TCP and IP. As a result, they should not be compared.
  • WebSockets establish a TCP connection and allow data to flow from the client or the server, which a unidirectional characteristic of RESTful HTTP cannot deliver. However, to distinguish between the usage of these protocols, we can state that WebSockets are not a publish/subscribe medium but are utilized in an environment to support pub/sub-architectures. They offer alternative options for a two-way transfer messaging system using the HTTP protocol.
  • WebSocket servers can transmit messages to individuals or groups of individuals. Unlike HTTP, which requires a request to open and close, they are always open channels for bidirectional data flow.
  • MQTT is a common pub/subsystem protocol. While MQTT describes how distinct computers can communicate with one another, they can also communicate on the same channel. Computers that publish messages with defined subjects on the channel can receive messages from machines that subscribe to those topics.
  • WebSockets are specifically built for client-server point-to-point connections. On the other hand, MQTT offers more abstraction on top of the basic message transmission mechanism, allowing numerous interested machines to subscribe to the topic of their choice. As a result, communications can sometimes be routed by topic so that different machines can share a common interest, and a server can opt to filter messages by topics while still receiving all messages.
  • WebSockets were first designed for full-duplex communication between browsers and servers. It can be used to connect embedded devices, also known as Azure IoT hub devices, although it cannot hold signals very well. MQTT was created specifically for IoT devices. Its design principles are to save network bandwidth while providing delivery certainty.
  • These concepts are appropriate for Azure IoT hub devices due to their low bandwidth and battery power.

MQTT is more suitable than WebSocket based on embedded systems in various ways:

  1. At the protocol level, MQTT supports pub/sub and Azure IoT hub.
  2. MQTT gives high-quality service.
  3. MQTT has a low communication overhead.
  4. MQTT is designed primarily for low-band communication channels and a small number of devices.
  • One of the significant similarities between MQTT and web socket is that they both use TCP. To put it another way, MQTT is like our courier services, which frequently assist in delivering our messages. At the same time, web sockets may be thought of as the road that assists in moving our courier services, which in turn assists in delivering our messages.
  • One of the main advantages of MQTT is that it has many capabilities that support all Azure IoT hub devices, and there are many practical implementations on both the client and server sides.
  • MQTT generally works as follows: the client-server subscribes to a channel, and when that channel receives fresh data, it sends it immediately to the device.
  • Another fantastic feature of MQTT is the ability to alter the priority, also known as QoS (Quality of service).
  • On the other hand, web sockets are often standardized; it’s one of the most significant ways to provide full push or pull communication that HTTP protocols cannot provide. Because there are so many IoT devices available, they create an overhead. Another downside of using web sockets is that we must make our protocol.


Hopefully, this article has helped you easily understand the fundamentals of MQTT and Websockets and their key differences. You must also evaluate the type of devices you are dealing with, and based on that, you may need to choose solutions such as MQTT over a web socket that uses both.

The akenza IoT platform allows the connecting of IP-enabled devices via MQTT (along with HTTP, CoAP, and LoRaWAN) and serves as the system’s MQTT broker (via Eclipse Mosquitto). Akenza provides a low-code IoT platform that enables businesses to create IoT goods and services by connecting, controlling, and managing such devices. Because of its numerous output connectors and interfaces, Akenza enables easy data processing in third-party applications. Long-term connections have been built with key clients such as the Facility Management Provider ISS Switzerland, Georg Fischer, and different SMEs.

Paul Petersen