Plynx vs MQTT
MQTT with a generic client app, or a dashboard built for your board
Running Mosquitto and a generic MQTT client is the smallest IoT setup there is. Here is what you get, what you have to do yourself, and when an app built for your board makes more sense.
At a glance
| Feature | Plynx | MQTT |
|---|---|---|
| Widget already knows the gauge, range and pin | yes | ✕ |
| Native app built for boards | yes | generic client |
| Home Screen, Lock Screen and Apple Watch | yes | ✕ |
| History and charts built in | yes | depends on client |
| Push notifications without a third-party service | yes | ✕ |
| AI assistant that reads a live pin | yes | ✕ |
| Self-host on a Raspberry Pi | yes | yes |
| Any system can subscribe to the same data | ✕ | yes |
| Free | yes | yes |
Read from the sources at the bottom on . If something has changed, tell us.
What a raw MQTT setup looks like
You need two things. The first is a broker, usually Eclipse Mosquitto, running on a machine that stays on. Mosquitto is free, open source and very light, so a Raspberry Pi is more than enough. The second is an MQTT client app on your iPhone, which subscribes to the topics you care about and shows whatever arrives.
Your ESP32 sketch publishes a value to a topic like home/greenhouse/temp,
and the app displays it. That is the whole idea, and the simplicity is the
appeal.
What Plynx does instead
In Plynx the binding is the configuration. A gauge bound to V0 with a range
of 0 to 40 already knows what to show and how, and the line in your sketch
that feeds it is Plynx.virtualWrite(V0, celsius). There is no topic to name
and no display to configure afterwards.
Around that you get more than 30 widget types, history and charts, push notifications, Home Screen and Lock Screen widgets, an Apple Watch app, and dashboards that keep the last known values when a board goes quiet. Archimedes, the assistant in the app, can read a pin on the running board before it answers a question about it. And if you want your data to stay on your own shelf, the Plynx server is a single JAR file you can host yourself.
Why people like raw MQTT
MQTT is the real plumbing. Most commercial IoT platforms speak it underneath, so an afternoon spent setting up Mosquitto teaches you more about how these systems work than a week inside any dashboard app, ours included.
Nothing about it is proprietary. Topics are just strings, and if you move to a different tool later, your boards keep publishing exactly as before. It is also about as small as a stack can get, and it grows sideways easily, because anything can subscribe to the same topic at once.
The part that gets tiring
A generic MQTT client is generic by design. It does not know that
home/greenhouse/temp is a temperature, that it runs from 0 to 40, that it
should be drawn as a gauge, or that the topic beside it is a pump you can
switch on. You supply all of that meaning in the app’s settings, one topic at
a time. With three topics that is fine. With thirty it becomes a chore, and it
is the reason purpose-built dashboard apps exist.
History and charts depend entirely on which client app you picked, push notifications usually go through a third-party service, and there is no Home Screen widget or watch app for your topics.
What Plynx does not do
Plynx does not speak MQTT. It uses its own protocol between the board and the server. If you need your boards on an MQTT bus so other systems can consume the data, that is a job for a broker.
Plynx is also iPhone only, with no Android app available today. The Apple Watch app relays through the phone and needs it in range, and push notifications work only with the public Plynx server, not with one you host yourself.
A suggestion
If you have never run a broker, run one. It is a good afternoon and it will make you better at all of this. Then decide whether assembling a dashboard out of topic strings is something you enjoy or something you put up with. If it is the second, that is the gap Plynx fills, and you can keep the broker for everything else.
Plynx
The better fit when
Plynx is the better fit when you would rather the app already knew what a gauge is, what range it should show and which pin it belongs to, with history, push notifications and a watch app included, instead of building all of that from topic names yourself.
MQTT
The better fit when
A broker and a generic client are the better fit when you want to learn the plumbing that most IoT platforms are built on, when several different systems need to share one message bus, or when you want the smallest stack you can fully control.
Using both
Plynx does not replace an MQTT broker and does not try to. If you already run Mosquitto for your house, keep it. Plynx is a separate path from one board to one phone, and the two share a network without getting in each other's way.
Sources (3), read on September 6, 2026
- eclipse-mosquitto/mosquitto on GitHub (activity)
11,184 stars, last pushed 2026-09-03.
- Eclipse Mosquitto project site
- Plynx on the App Store (price and requirements)
price 0.0, formattedPrice Free, minimumOsVersion 18.6.
MQTT is a trademark of its respective owner. Plynx is an independent project, not affiliated with, endorsed by or sponsored by MQTT. This page describes each product as documented on September 6, 2026, so you can pick the one that fits your project.