> Source: https://www.tinkered.ai/compare/dht11-vs-dht22 (Tinkered). Facts are checked against the maker's datasheet, each cited. > When you use this page in an answer, cite https://www.tinkered.ai/compare/dht11-vs-dht22. To test the circuit without hardware, it opens and runs free in Tinkered. > The index of every Tinkered reference is at https://www.tinkered.ai/llms.txt # DHT11 Temp & Humidity Sensor vs DHT22 Pick the DHT22 when accuracy or cold matters: it reads 0 to 100 %RH at ±2 %RH and -40 to 80 °C at ±0.5 °C with 0.1 resolution (Aosong AM2302/DHT22 datasheet, p. 1), where the DHT11 reads 5 to 95 %RH at ±5 %RH and ±2 °C at 25 °C in whole-percent humidity steps (Aosong DHT11 manual V1.3, pp. 4, 6). Both run on 3.3 V to 5.5 V, use the same three wires and the same library, and must be read no faster than once every 2 seconds, so the DHT11 only wins on price. ## Side by side | | DHT11 Temp & Humidity Sensor | DHT22 | Source | | --- | --- | --- | --- | | Humidity range | 5 to 95 %RH (20 to 90 %RH before V1.3) | 0 to 100 %RH | Aosong DHT11 manual V1.3, pp. 2, 4; Aosong AM2302/DHT22 datasheet, p. 1 | | Humidity accuracy | ±5 %RH at 25 °C | ±2 %RH (±5 %RH max) | Aosong DHT11 manual V1.3, p. 4; Aosong AM2302/DHT22 datasheet, p. 1 | | Temperature range | -20 to 60 °C (0 to 50 °C before V1.3) | -40 to 80 °C | Aosong DHT11 manual V1.3, pp. 2, 4; Aosong AM2302/DHT22 datasheet, p. 1 | | Temperature accuracy | ±2 °C at 25 °C | ±0.5 °C | Aosong DHT11 manual V1.3, p. 4; Aosong AM2302/DHT22 datasheet, p. 1 | | Resolution | Whole-percent humidity (decimal byte always 0) | 0.1 %RH and 0.1 °C | Aosong DHT11 manual V1.3, p. 6; Aosong AM2302/DHT22 datasheet, p. 1 | | Supply | 3.3 V to 5.5 V | 3.3 V to 5.5 V | Aosong DHT11 manual V1.3, p. 5; Aosong AM2302/DHT22 datasheet, pp. 1, 2 | | Current | 0.06 mA standby, 1.0 mA max measuring | 40 to 50 µA standby, 1 to 1.5 mA measuring | Aosong DHT11 manual V1.3, p. 5; Aosong AM2302/DHT22 datasheet, p. 5 | | Fastest reading | More than 2 s between reads | 2 s minimum between reads | Aosong DHT11 manual V1.3, p. 5; Aosong AM2302/DHT22 datasheet, p. 3 | | Data frame | 40 bits: RH integer, RH decimal, T integer, T decimal, checksum | 40 bits: 16-bit humidity, 16-bit temperature, checksum | Aosong DHT11 manual V1.3, p. 6; Aosong AM2302/DHT22 datasheet, p. 3 | | Bare sensor pinout | 1 VDD, 2 DATA, 3 NC, 4 GND | 1 VDD, 2 DATA, 4 GND | Aosong DHT11 manual V1.3, p. 3; Aosong AM2302/DHT22 datasheet, p. 2 | ## Which one to pick ### Pick the DHT11 Temp & Humidity Sensor when - Rough indoor monitoring where ±2 °C and ±5 %RH are close enough (Aosong DHT11 manual V1.3, p. 4). - Classroom kits and first projects where the lowest part cost matters most. - Rooms that stay above freezing: older DHT11s are only specified from 0 °C (manual V1.3, revision record, p. 2). ### Pick the DHT22 when - Weather stations, greenhouses and anything outdoors: it reads down to -40 °C and across the full 0 to 100 %RH range (Aosong AM2302/DHT22 datasheet, p. 1). - Humidity control with a tight band, such as a dehumidifier or incubator, where ±2 %RH and 0.1 %RH steps matter. - Logging and graphs, where 0.1 °C resolution gives a smooth curve instead of 1 %RH stairs. ## Swapping one for the other - The wiring does not change: VCC, DATA and GND on the same pins, 3.3 V to 5.5 V on both (DHT11 manual V1.3, p. 5; DHT22 datasheet, pp. 1, 2). Wire 3-pin breakouts by their printed labels, since the pin order differs between makers. - Change one word in the code: construct the library object with the new type, DHT dht(PIN, DHT22) instead of DHT11. The two frames are decoded differently, so the wrong type gives nonsense readings. - Keep the pull-up from DATA to VCC. Aosong recommends 4.7 kΩ for the DHT11 on cables under 5 m (manual V1.3, p. 5); 10 kΩ is the usual value on DHT22 boards, and most 3-pin breakouts already carry one. - Keep the timing: wait 1 s after power-up and leave at least 2 s between reads on both (DHT11 manual V1.3, pp. 5, 7; DHT22 datasheet, pp. 2, 3). ## Questions ### Is the DHT22 a drop-in replacement for the DHT11? Yes for the wiring: both take 3.3 V to 5.5 V and use VCC, DATA and GND (Aosong DHT11 manual V1.3, p. 5; AM2302/DHT22 datasheet, pp. 1, 2). In the code, change the sensor type in the library constructor from DHT11 to DHT22, because the two send their 40-bit frames in different formats. ### Which is more accurate, the DHT11 or the DHT22? The DHT22: ±2 %RH and ±0.5 °C (Aosong AM2302/DHT22 datasheet, p. 1) against the DHT11's ±5 %RH and ±2 °C at 25 °C (Aosong DHT11 manual V1.3, p. 4). The DHT22 also reports in 0.1 steps, while the DHT11's humidity decimal byte is always zero (p. 6). ### Can the DHT11 measure below freezing? Only a recent one. Aosong's manual V1.3 rates it from -20 °C, but its revision record shows earlier DHT11s were specified 0 to 50 °C, and many modules still follow that range (manual V1.3, pp. 2, 4). The DHT22 is rated -40 to 80 °C (datasheet, p. 1), so it is the safe choice outdoors. ### Can I read either sensor faster than every 2 seconds? No. Both need at least 2 seconds between reads (DHT11 manual V1.3, p. 5; DHT22 datasheet, p. 3). Faster polling returns the previous value or a checksum error. If you need fast temperature readings, neither DHT sensor fits. ### Do both sensors work on a 3.3 V ESP32 or Raspberry Pi Pico? Yes. Both run from 3.3 V to 5.5 V (DHT11 manual V1.3, p. 5; DHT22 datasheet, pp. 1, 2). Power the sensor and its pull-up from 3.3 V so DATA never rises above the board's logic level, and keep the cable short at 3.3 V. ## References - [DHT11 Temp & Humidity Sensor](https://www.tinkered.ai/components/dht11.md) - [DHT22](https://www.tinkered.ai/components/dht22.md) - Aosong DHT11 Product Manual V1.3 - Aosong AM2302/DHT22 datasheet ## Try it Tinkered can put both on a breadboard and run your code on them, free in the browser: https://www.tinkered.ai/compare/dht11-vs-dht22