What's the lowest-power IoT connectivity option?

Bluetooth LE and Zigbee are both built around low duty cycles and can run for months to years on a small battery, depending on how often the device transmits. Wi-Fi draws far more power and usually needs mains power or frequent recharging.

Which IoT protocol has the longest range?

For a single hop, Wi-Fi typically reaches farther indoors than Bluetooth LE or Zigbee. For whole-building coverage, mesh protocols like Zigbee and Thread can outperform Wi-Fi by relaying through multiple devices rather than relying on one hop back to a router.

Do I need MQTT if I'm just building a smart home device?

Not directly. MQTT is a messaging layer that usually sits behind the scenes, often used by hubs and cloud platforms to move data after it's already been collected over Wi-Fi, Zigbee, or Thread. Most consumer devices never implement MQTT themselves.

CONNECTIVITY

How to choose an IoT connectivity protocol

There's no single best protocol. There's a best protocol for a specific range, power budget, and data volume, and the fastest way to pick wrong is to start from what's newest instead of what the device actually needs.

Start with three questions

How often does the device need to transmit? A door sensor that reports twice a day has a completely different power budget than a camera streaming video continuously.
How far does the signal need to travel, and through what? Line-of-sight range and through-wall range are not the same number, and mesh protocols change the math further by relaying through other devices.
Is the device on battery or mains power? Mains-powered devices can afford Wi-Fi's higher draw. Battery devices generally can't if they need to last more than a few weeks.

Typical figures, not lab maximums

Wi-Fi~30-50m indoor · high power · high bandwidth

Bluetooth LE~10-30m · very low power · low bandwidth

Zigbee~10-20m per hop, mesh extends it · low power

Thread / Matter~30m per hop, mesh · low power · IP-based

MQTTmessaging layer, not radio · runs over Wi-Fi/Ethernet

A working default

For a battery device reporting occasionally, in range of other similar devices, a mesh protocol like Zigbee or Thread is usually the right call. For anything mains-powered that needs to move real bandwidth, like a camera, Wi-Fi is the direct answer. For a wearable, Bluetooth LE almost always wins on the battery-life math alone, as covered in the Bluetooth LE guide. MQTT rarely competes with any of these directly, since it's a messaging layer that runs on top of whichever radio protocol already got the data moving.

Frequently asked

What's the lowest-power option? Bluetooth LE and Zigbee, both built around low duty cycles.

What has the longest range? Wi-Fi per hop; mesh protocols like Zigbee and Thread for whole-building coverage.

Do I need MQTT for a smart home device? Usually not directly, it typically runs behind the hub or cloud platform.