MQTT vs HTTP for IoT: Why MQTT is a Better Choice

MQTT (Message Queuing Telemetry Transport) and HTTP (Hypertext Transfer Protocol) are two different communication protocols, each with its own strengths and weaknesses. The choice between MQTT and HTTP depends on the specific requirements of your application. Here are some reasons why MQTT might be a better choice than HTTP in certain scenarios:

In a world where devices and computers need to talk to each other, we have different ways for them to do it. Two of these ways are called MQTT and HTTP. MQTT is like a super-efficient, quick, and quiet messenger. It’s really good for sending small updates between devices, like telling a temperature sensor to send its data to your phone in real-time. On the other hand, HTTP is like sending emails or making phone calls. It’s good for when you ask for something, like loading a webpage, and then you get a reply. But for fast and constant updates, MQTT is often a better choice. This article will explain why.

What is MQTT?

MQTT, which stands for Message Queuing Telemetry Transport, is a lightweight and efficient messaging protocol designed for reliable communication between devices in a network. It follows a publish-subscribe model, where devices (or clients) communicate through a central server called a broker.

How it Works?

In MQTT, devices can either be publishers, subscribers, or both. Publishers send messages (or “publish” them) to specific topics on the broker, while subscribers express their interest in specific topics by subscribing to them. When a publisher sends a message to a topic, the broker ensures that all subscribers interested in that topic receive the message. This decoupled approach allows for asynchronous and real-time communication, making MQTT well-suited for applications where devices need to exchange information quickly, such as in the Internet of Things (IoT). Additionally, MQTT offers different Quality of Service (QoS) levels, allowing users to choose the level of message delivery reliability, ranging from “at most once” (where messages may be lost) to “exactly once” (guaranteeing message delivery but with more overhead). This flexibility makes MQTT adaptable to various communication scenarios, from low-latency sensor data transmission to more reliable, business-critical applications.

What is HTTP?

HTTP, or Hypertext Transfer Protocol, is the fundamental protocol of the internet used for transmitting and receiving data between web browsers and web servers. It forms the basis for how information is exchanged on the World Wide Web. HTTP operates on a request-response model: when you type a web address into your browser and hit “Enter,” your browser sends an HTTP request to a remote web server. This request typically specifies the desired web page or resource, and the server responds with an HTTP response, delivering the requested content along with information about the status of the request. This response may include text, images, videos, or any other data that comprises a web page.

HTTP is designed to be simple and human-readable, using plain text as its communication medium. It employs a stateless architecture, meaning each request is independent and doesn’t retain information about past interactions, simplifying server management and promoting scalability. Moreover, HTTP’s use of hyperlinks connects web pages, enabling you to navigate seamlessly between different pages on the internet by simply clicking on links. In essence, HTTP is the backbone of web communication, allowing us to access and interact with a vast array of information and services on the web.

Difference Between MQTT and HTTP

Here are some reasons why MQTT might be a better choice than HTTP in certain scenarios:

Low Overhead: MQTT is designed for low overhead communication. It uses a publish/subscribe model, which is more efficient for sending small packets of data. HTTP, on the other hand, has more overhead due to its request/response model and headers, making it less efficient for frequent and small data updates.

Real-time and Asynchronous: MQTT is ideal for real-time and asynchronous communication. It allows for push notifications and immediate updates when data changes, making it suitable for applications like IoT (Internet of Things) where sensor data needs to be transmitted in real time. In contrast, HTTP is typically request-driven, which can introduce latency.

Publish/Subscribe Model: MQTT’s publish/subscribe model is well-suited for scenarios where multiple clients need to be updated with the same information. Subscribers can receive data without needing to request it, making it more efficient for broadcasting data to multiple consumers.

Low Bandwidth and High Latency Environments: MQTT is designed to perform well in low bandwidth and high latency environments. It uses a lightweight binary protocol that reduces the amount of data exchanged. HTTP can be less efficient in such scenarios due to its textual nature and additional headers.

Reduced Battery and Data Usage: MQTT is often used in IoT applications, where devices may have limited battery life and data plans. MQTT’s efficiency can help conserve power and reduce data usage compared to HTTP, which may require more frequent and larger data transfers.

Reliable Messaging: MQTT supports Quality of Service (QoS) levels, which allow you to choose the level of message delivery reliability, from at most once to exactly once. This can be critical in applications where data integrity is essential.

Scalability: MQTT brokers can handle a large number of connected clients, making it a scalable choice for applications with many devices or users. HTTP, while scalable, may require more resources to handle a similar number of connections.

Security: Both MQTT and HTTP can be secured, but MQTT’s lightweight nature means it can be a good choice for constrained environments where securing the communication is important but requires minimal overhead.


Communication ModelPublish-SubscribeRequest-Response
EfficiencyLow overhead, suitable for IoTMore overhead, suitable for web
Real-timeSupports real-time and pushTypically request-driven, not real-time
AsynchronousAsynchronous messagingSynchronous request-response
Message DeliverySupports Quality of Service (QoS) levels for reliabilityNo built-in QoS levels
Publish-SubscribeFollows a publish-subscribe model, allowing multiple clients to receive the same dataClient-server model, requiring explicit requests
ScalabilityScales well for a large number of clientsScales but may require more resources for similar loads
Data TypesSuitable for lightweight data transmission, such as sensor dataCommonly used for transferring web content, including text, images, videos, etc.
Low BandwidthEfficient in low bandwidth and high latency environmentsMay be less efficient in such environments
SecurityCan be secured with authentication and encryptionCan also be secured with authentication and encryption
UsageCommonly used in IoT, machine-to-machine (M2M), and real-time data applicationsFundamental for web browsing, web services, and human interactions with websites
ProtocolBinary protocol, lightweightText-based protocol, more overhead
Connection TypePersistent connections are commonTypically stateless, with separate connections for each request

It’s important to note that MQTT and HTTP serve different use cases, and the choice between them depends on your specific application requirements. In many cases, they can be used together in a complementary manner, with HTTP serving for certain types of interactions (e.g., web-based interfaces) and MQTT for real-time, low-latency, and efficient data exchange, especially in IoT and machine-to-machine (M2M) communication scenarios.

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