Generate realistic MQTT test data without real devices

MQTT client values Simulator

$50 · Free trial · 30 minutes

Your sensors aren't ready. Your deadline is.

MQTT Simulator streams realistic plant and device data to your broker in minutes — so you can build dashboards, prove alarm rules and demo the whole system long before the hardware arrives.

Full product for 30 days. No credit card. No .NET or other prerequisites.

Stop waiting on hardware. Stop writing throwaway scripts.

Every IoT project hits the same wall: the software is ready to test, but the data isn't.

Without it The usual workarounds

Weeks lost waiting for devices to be installed and commissioned
One-off Python scripts that publish the same flat value forever
Alarm logic that's never tested until something really goes wrong
Demos that depend on a live site — and fail when it's quiet
No way to tell if the broker silently drops what you send

With MQTT Simulator Data on day one

Hundreds of believable signals flowing in minutes, from a spreadsheet
Values that drift, cycle and ramp like the real equipment
Any alarm triggered on demand with one click — and cleared with another
A repeatable demo plant that runs whenever and wherever you need it
Built-in proof that every message actually reached its subscriber

Everything you need to simulate a plant — in your browser

Real screens from the product, running the included 24-topic sample plant.

See every message as it leaves

One dashboard tells you everything: connection state, live message rate, totals, and a scrolling log of exactly what was sent.

✓ Start and stop the whole simulation with one click
✓ Warns you before starting if the broker isn't connected
✓ Errors and dropped messages are counted, never hidden
✓ Reconnects by itself if the broker goes away

Trigger any alarm, on demand

Force a topic to any value — even outside its normal range — to push a reading over its threshold. The button turns red and reads Unforce , so nobody forgets what's pinned.

✓ Test high, low and state alarms without touching a real machine
✓ Send a single message instantly with Once
✓ Duplicate a topic in one click, and rename any topic without losing its history
✓ Search, filter and switch hundreds of topics on or off

Data that behaves like the real thing

Choose how each signal moves — a temperature that drifts, a pressure that cycles, a counter that climbs — and preview the curve before you save.

✓ Walk, random, ramp and sine generators, plus on/off and states
✓ Ranges, step size, precision, units and publish rate per topic
✓ Plain values or JSON with unit and timestamp; QoS and retain
✓ Change anything while it runs — it takes effect on the next message

Set up hundreds of topics from Excel

Import a CSV file and see exactly what will change before anything does. Mistakes are listed by line with a plain-English reason — the good rows still import.

✓ Merge into what's loaded, or replace it entirely
✓ Duplicate and look-alike topic names are caught before they split your data
✓ Export to CSV and re-import to the identical setup
✓ Save scenarios as profiles: "normal shift", "alarm storm"

Know your data actually arrived

A broker can accept a message and quietly throw it away. Round-trip verification subscribes to what you send and shows anything that never came back, with real latency figures.

✓ Any MQTT 3.1.1 or 5.0 broker, local or cloud
✓ Username and password, TLS and mutual TLS
✓ Saved passwords are encrypted, never shown again

Built for the people who build connected systems

Dashboards & HMIs

Build Grafana, Node-RED, SCADA and custom screens against live-looking data with every range and state your plant will produce.

Alarms & integrations

Repeatable scenarios for alarm rules, historians, rule engines and cloud pipelines — and load tests at thousands of messages a second.

Demos that never fail

Show the full system at a customer meeting or trade stand with nothing to ship, wire or power — on a laptop.

A safe practice plant

Let operators and new engineers learn on a plant that misbehaves exactly when you want it to, and never breaks anything.

Fast to adopt

One installer, no prerequisites. The included sample plant gets you to live data before your coffee cools.

Secure by default

Only reachable from your own computer unless you choose otherwise. Encrypted credentials. TLS checks stay on.

Always on

Runs as a Windows service that starts with the computer — ideal for shared test benches and demo rigs.

Live data in four steps

About five minutes, start to finish.

Install

Run the installer and keep the defaults: a Windows service on port 5080 . Your browser opens when it's done.

Connect

It's already connected to a free public test broker. For your own, open Brokers , enter the address and click Connect .

Load topics

On Topics , click Import CSV and pick the included plant.csv — 24 ready-made signals.

Go live

Click Start All on the Dashboard and watch messages arrive in your own MQTT client.

Your own plant is one spreadsheet away: one row per topic, as above. The public test broker is visible to anyone — great for a first look, but switch to your own broker before sending anything that matters.

Try everything. Pay when it's earning its keep.

Every feature is in every plan. Plans differ only in how many topics publish at once.

✓ Every feature
✓ Unlimited topics
✓ No credit card, no sign-up
✓ Every feature
✓ The topic capacity your project needs
✓ Perpetual or time-limited
✓ Installs in seconds, no internet activation
✓ Every feature
✓ Up to 10 topics at a time
✓ Never stops working

The simulator never stops because of its licence. Topics over a limit pause with their settings kept, and resume as soon as the limit is raised.

Get the most from your simulation

Use your real topic names , so everything built against the simulator works unchanged on the real plant.
Match the mode to the physics: walk for anything with inertia, sine for cycles.
Keep scenarios in CSV next to your project — easy to review, share and version.
Run round-trip verification once on every new broker.
Real or confidential data on the public test broker. Anyone can read it.
Opening the web interface to the network unprotected — it has no login. Put it behind an authenticating proxy if colleagues need it.
QoS 2 everywhere. Use 0 for fast telemetry; keep 1 or 2 for state changes.
Going flat out on day one. Start with modest rates and raise them while watching Dropped .

Questions, answered

Any broker that speaks MQTT 3.1.1 or 5.0 — Mosquitto, HiveMQ, EMQX and others, on your network or in the cloud — with anonymous, username and password, TLS or mutual TLS connections.

Just the installer. It runs on 64-bit Windows 10, Windows 11 and Windows Server 2016 or later, needs about 110 MB of disk, and carries everything else it needs. You use it from any modern browser.

It sustains 10,000 messages a second across 1,000 topics without dropping any. Each topic publishes on its own schedule, from every 100 milliseconds to hours apart.

No — it publishes only. It is designed to stand in for devices sending data, which is what dashboards, alarms and data pipelines consume.

Open the Licence page in the app and send us the machine fingerprint shown there along with the number of topics you need. You'll receive a licence file to install on the same page — no internet connection or activation server required.

Nothing stops. The simulator carries on with up to 10 topics publishing at a time. Your other topics keep their settings and resume the moment a licence is installed.

The web interface is only reachable from the computer it runs on by default. The installer can open it to your office network, but it has no login, so we recommend putting it behind an authenticating proxy for shared use.

Have live data flowing before lunch.

Download MQTT Simulator and try every feature free for 30 days.