WiFi vs BLE vs LoRa — how do you choose for an IoT product?

The choice between WiFi, BLE, and LoRa depends on four primary factors: data rate requirements, range, power budget, and network infrastructure. WiFi (802.11b/g/n/ax) delivers the highest throughput (tens of Mbps), operates over existing infrastructure (routers, cloud connectivity), and supports TCP/IP natively — making it ideal for devices that need internet connectivity, stream video or audio, or transfer large payloads like firmware images. The cost is power: a WiFi SoC like ESP32 draws 80-240 mA during TX/RX, making it impractical for battery-powered devices that must last months. WiFi works best for line-powered products (smart plugs, cameras, displays) or devices with large rechargeable batteries and infrequent transmission windows.

BLE is the sweet spot for short-range, low-power personal devices: wearables, fitness trackers, medical sensors, smart locks, and phone-connected accessories. Range is typically 10-30 meters indoors (up to 100+ meters line-of-sight with BLE 5.0 Long Range coded PHY), data rate is modest (1-2 Mbps PHY, roughly 100-700 kbps application throughput), and power consumption is micro-amp-level between connection events. BLE requires a smartphone or gateway for cloud connectivity, which is acceptable for consumer products but adds complexity for industrial deployments. BLE Mesh extends the topology to many-to-many but adds latency and complexity.

LoRa occupies the long-range, ultra-low-power, low-data-rate niche: agricultural sensors, utility meters, asset trackers, environmental monitoring — any device that sends small payloads (tens of bytes) infrequently (once per hour or less) over distances of 2-15 km. LoRa operates in sub-GHz ISM bands (868 MHz in EU, 915 MHz in US), which penetrate buildings and foliage far better than 2.4 GHz. The tradeoff is throughput: LoRa's maximum data rate is roughly 50 kbps (SF7, 500 kHz BW), and typical LoRaWAN deployments use much less. The decision framework in an interview should consider: Can the device be plugged in? If yes, WiFi. Does it need phone connectivity and short range? BLE. Does it need multi-kilometer range with tiny payloads on battery? LoRa. Real products often combine two radios — for example, BLE for configuration and local connectivity plus LoRa for long-range data reporting.