8 of the 13 features in our table differ between the HC-SR04 and the JSN-SR04T.
Ultrasonic · 2 cm to 4 m · Trigger and echo pulses · 5 V
The classic ultrasonic module: 2 cm to 4 m, a wide beam, and it sees glass and dark objects.
Watch out: It runs at 5 V and its echo pin outputs 5 V: use a divider on a 3.3 V board. Soft surfaces and steep angles return weak echoes.
Ultrasonic · 25 cm to 4.5 m · Trigger and echo pulses/UART · 5 V
A waterproof ultrasonic probe on a cable, made for tanks, wells and outdoors: 25 cm to 4.5 m.
Watch out: Nothing closer than about 25 cm. 5 V. ESPHome reads it over UART, a mode you select with a resistor or pads on the board.
| Feature | HC-SR04 | JSN-SR04T |
|---|---|---|
| Range | 2 cm to 4 m | 25 cm to 4.5 m |
| Accuracy | down to 3 mm (maker figure) | resolution about 0.5 cm |
| Field of view | 15° (“measuring angle” in the datasheet) | 50° |
| Interface | Trigger and echo pulses | Trigger and echo pulses, UART |
| Current while measuring | 15 mA | 30 mA |
| Current between readings | – | 5 mA |
| Waterproof | No | Yes (sealed probe) |
| ESPHome | ultrasonic | jsn_sr04t |
Same on both: technology · supply · status.
Open the sensor comparison →Tick what your project needs and see which sensor fits best.
The HC-SR04 offers readings closer in. The JSN-SR04T offers a longer range and a waterproof head for tanks and outdoors.
Range: 2 cm to 4 m for the HC-SR04, 25 cm to 4.5 m for the JSN-SR04T. Accuracy: down to 3 mm (maker figure) and resolution about 0.5 cm. The target’s colour and material, and sunlight, change both.
Often yes: both use trigger and echo pulses. Change the driver or, in ESPHome, the component (ultrasonic → jsn_sr04t).
Figures from the makers’ datasheets and product pages and the ESPHome documentation, checked in November 2026.