MIMIC^® MQTT Simulator: simulate thousands of MQTT devices

MIMIC MQTT Simulator creates a lab of up to 100,000 simulated MQTT sensors, gateways and devices. Each one is a real MQTT client with its own client ID, credentials and, if you want, its own IP address, publishing and subscribing to your broker or IoT platform. Use it to load test brokers, develop and demo IoT applications, and train teams without buying hardware.

Try it now, free and without registration, in an online MQTT lab.

What MIMIC MQTT Simulator simulates

MQTT is a light-weight publish and subscribe protocol over TCP/IP for the Internet of Things, designed for small code footprints and limited bandwidth; a message broker delivers each message to the clients subscribed to its topic. MIMIC simulates the clients, at scale.

• Publishers and subscribers. Every simulated device can publish to many topics, subscribe to many topics including wildcards, or both.
• MQTT 3.1.1 and MQTT 5.0, chosen per device, including MQTT 5 CONNECT and PUBLISH properties.
• Secure connections to brokers, MQTT gateways, load balancers and clients, with TLS 1.1, 1.2 and 1.3, user name and password, OAuth 2.0 or JSON Web Tokens (JWT).
• QoS levels, retained messages and Last Will, connect and reconnect behaviour.
• Any payload: ASCII, JSON or binary, stateless or stateful, including the Sparkplug B, SmartREST, LWM2M-MQTT and TR50 formats.
• A different IP address for every device, as on a LAN at the edge, or thousands behind one address, as behind NAT.
• Faulty and hostile devices: messages of varying length and frequency, malicious content to test security, and a faulty sensor network to test how robust your subscribers are.
• Recording: capture real sensors with the mqttrec proxy, or from a packet capture, and replay them at scale.

MQTT broker load testing at scale

Gambit has published these tests of MIMIC simulated sensors against MQTT brokers:

MIMIC also measures end-to-end MQTT latency, from the moment a simulated sensor publishes to the moment your subscriber receives it. Try it in the MQTT latency lab.

Works with your IoT platform

Gambit documents MIMIC with more than 50 MQTT brokers and IoT platforms. Each platform below has a ready lab with a step-by-step tutorial:

• Amazon AWS IoT Core: simulated sensors publish JSON telemetry to your AWS account in 15 minutes; a replacement for the deprecated AWS IoT Device Simulator solution
• Microsoft Azure IoT Hub
• Cumulocity IoT, free demo
• Losant, free demo
• Ubidots, free demo
• TagoIO, free demo
• Sparkplug applications, free demo
• Eclipse Hono, free demo

On premises and at the edge it works with Mosquitto, HiveMQ, EMQTT (EMQX), VerneMQ, RabbitMQ, Ignition, ThingWorx, Node-RED, Amazon Greengrass and more.

Industrial IoT, Sparkplug B and the Unified Namespace

MIMIC implements Sparkplug B, the Industrial IoT standard used by the Ignition MQTT Edge module, including the state machine every connecting device has to support. Simulated EON nodes and their devices publish Sparkplug metrics to your broker exactly as real ones do, so you can fill a Unified Namespace with realistic device data before any hardware exists. Try the free Sparkplug lab.

MIMIC MQTT Simulator applies to these publish/subscribe areas: Industrial IoT, IoT smart city, fleet management, asset tracking and the Unified Namespace. The Applications tab below shows a vehicle fleet simulation driving a Losant dashboard, and 10,000 simulated sensors publishing to Eclipse Amlen.

It is designed to reduce the risk of deploying large Internet of Things applications: rapidly prototype alternatives, build a proof of concept that replaces or supplements real devices, and load test many scenarios. IoT application vendors use it to show their customers that their products handle the scale of connections, topics and message types they will meet in heterogeneous environments, and to produce scalability benchmarks for sensors, message volume and topics.

Try the MQTT simulator online

• Free demo lab: 40 simulated Bosch sensors publishing JSON telemetry to four public brokers, no registration or credit card
• Free MQTT 5 lab
• Your own MQTT lab with 10, 100, 1,000 or 10,000 sensors publishing to any internet-accessible broker, rented on AWS Marketplace
• All MQTT labs

Control the simulation while it runs

• Start, stop and change each device individually or in groups, from the GUI, the command line or APIs in Java, C++, Perl, Python, Tcl, PHP and JavaScript
• Change the telemetry of a running sensor and see it in your subscriber in real time
• Scale from 10 sensors in an online lab to 100,000 on your own systems
• Combine MQTT with SNMP simulation of the same device
• Runs on Windows, Linux, AWS, Azure and Google Cloud (details)

MQTT simulator FAQ

How many MQTT devices can MIMIC simulate?

Up to 100,000 MQTT 3.1.1 or 5.0 sensors and devices. Published broker tests range from 1,000 to 100,000 connections (see above).

Does MIMIC work with my MQTT broker?

Yes, if your broker supports MQTT 3.1.1 or 5.0. Configuration notes for more than 50 brokers and platforms, including TLS settings, are in the MQTT compatibility guide.

Is there a free MQTT simulator trial?

Yes, two ways: the online labs are free to try, with no registration; and you can request a free evaluation copy, usually for two weeks, to install on your own systems.

Can MIMIC replace the AWS IoT Device Simulator?

AWS deprecated its IoT Device Simulator solution on 2025-01-29. MIMIC simulates devices that publish to AWS IoT Core, and the AWS IoT Core lab walks through the setup in 15 minutes.

Does it simulate Sparkplug B devices?

Yes: MIMIC implements Sparkplug B, and a free Sparkplug lab shows Sparkplug sensors behind EON nodes publishing to public brokers.

Can I measure MQTT latency?

Yes, end to end, from the simulated publisher through the broker to the subscriber, as in the MQTT latency lab.

Where does it run?

Windows, Linux, and virtual machines on AWS, Azure and Google Cloud. See supported platforms.

Video: MIMIC Sparkplug Simulator and Azure Event Grid