MQTT vs WebSocket

Updated March 20, 2023

Difference Between MQTT vs WebSocket

MQTT vs WebSocket in this, the MQTT is a lightweight publish/subscribe network protocol used to directly transport messages between devices/machines directly in the web browser. This protocol is ideal for IOT applications like Alexa as they don’t have a web browser to send or receive data. It is ideal for carrying signals and is mostly used for constrained devices with low-bandwidth, high latency, or unreliable network. It also enables you to send commands to control action, publish data and much more.

On the other side, WebSocket is a computer communication protocol that creates a two-way channel between a web browser & a server. It runs over a single TCP connection and solves HTTP limitations to allow low latency bidirectional communication. Using MQTT over Web socket helps in activating all of MQTT features which can be used for many use cases such as:

• Displaying the live information
• Enabling the push/alert notifications
• To check the current status of devices with the help of messages that are retained.
• Communicating very easily with mobile and web applications

Head to Head Comparison of  MQTT vs WebSocket

Below is the Top 7 comparison between MQTT vs WebSocket:

Key Differences of MQTT vs WebSocket

Given below are the major key differences between MQTT vs WebSocket:

• MQTT stands for MQ Telemetry transport, which is the key protocol in messaging over small devices. MQTT and Websockets are two different protocols lying in different layers like TCP, IP. Hence these should not be compared.
• But to understand the difference between the uses of these protocols, we can clearly say that WebSockets do not publish/subscribe medium, but they are used in an environment to support pub/sub-architectures. They provide alternate solutions over the HTTP protocol for a two-way transfer messaging system. WebSockets opens a TCP connection and lets the data flow either from the client or server, which cannot be provided by a unidirectional feature of RESTful HTTP, which is at the same level.
• WebSocket servers can send messages to clients/groups of clients. They are always open channel for bidirectional data transfer without request for open and close like HTTP.
• While MQTT defines how different machines can talk to each other, they can talk to the same channel. MQTT is a typical pub/subsystem. Publisher machines can publish any message with defined topics on the channel, and machines that subscribed to such topics can receive those messages.
• WebSockets are specially designed for point to point connections between a client and a server. However, MQTT adds on extra abstraction on top of the basic message sending mechanism such that multiple interested machines can subscribe to the topic of their interest. Hence sometimes messages can be routed by topic so that multiple machines can share a common interest, where a server can choose to filter messages by topics but can receive all the messages.
• WebSockets was initially developed for the full-duplex communication channel between browser and servers. It can be used for connectivity of embedded devices, or you can say IOT devices, but it will not be able to hold signals very well. MQTT has been specially designed for IOT devices. Its design principles are to minimize network bandwidth and provide assurance of delivery.
• These principles are ideal for IOT devices because their bandwidth and battery power are very low.

MQTT is more suitable than WebSocket in the context of embedded systems in various ways:

1. MQTT provides pub/sub at the protocol level.
2. MQTT provides quality of service.
3. MQTT incurs minimal overhead in communication.
4. MQTT is basically for small band communication channels and a limited number of devices.

• One of the similarities between MQTT and web socket is that both protocols are based on TCP. To understand better, MQTT is like our courier services which often help in delivering our messages, whereas we can imagine web sockets as the road that helps in transporting our courier services which in turn helps in delivering our message.
• One of the key advantages of MQTT is that by its virtue, it has a lot of features that support all the IoT devices, and there is a lot of practical implementations on the client and server-side.
• Basically, MQTT works like this; initially, the client-server will subscribe to a channel, and when this channel will receive new data, it will directly send that data to the device.
• Another brilliant feature of MQTT is that we get to set the priority also known as QoS (Quality of service), namely 0 (where the message is transmitted without any confirmation), 1 (confirmation is required for transmission of the message) and 2 (it makes use of a handshake process to deliver a message).
• On the other hand, web sockets are generally standardized in nature; it’s one of the best ways to achieve full push or pull communication that we cannot achieve by using the HTTP protocols. They become an overhead as there is a lot of IoT devices available. One other disadvantage we face while using these web sockets is setting up our own protocol.

MQTT vs WebSocket Comparison Table

Let’s discuss the top comparison between MQTT vs WebSocket:

MQTT	Websockets
MQTT is a typical pub/subsystem, and they are majorly used in small devices.	Mainly works in an environment that supports pub/sub-architectures.
We have the facility to set priority.	There is no feature available for setting the priority.
Majorly used in client and server applications.	Used for full web client applications as they are standardized and they achieve in full push/pull communications.
It incurs minimal overhead during communication.	There is a lot of overhead when we have a lot of IOT devices during communication.
Specifically designed for IOT devices with an aim to reduce the bandwidth and provides assurance of delivery.	Mainly developed for full-duplex/bidirectional communication channels.
MQTT and Websockets are similar to TCP and IP protocols; basically, they are one layer above the other.	They are a low-level protocol.
Multiples parties can be able to subscribe and publish messages.	Designed mainly for point to point communication.

Conclusion

I hope this article would have helped us understand the basics of MQTT and Websockets and the major differences between them. We also need to consider what kind of devices we are dealing with, and based on that; we may have to go for options such as MQTT over a web socket that uses both.

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This is a guide to MQTT vs WebSocket. Here we discuss the difference between MQTT vs WebSocket, along with key differences, infographics, & a comparison table. You can also go through our other related articles to learn more–

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