I am concerned whether I need to use a voltage divider to power my ESP8266 module. My concerns stem from the warnings that I have heard in multiple tutorials. Everyone seems to regard the ESP8266 as being very sensitive to supply voltage.

Has anyone use the ESP8266 with an supply voltage greater than 3.5 V? What were the effects? Is it even necessary to make a voltage divider?

I am asking because my application has limited real estate.

  • 2
    Surely you mean 3.3V :) Jan 9, 2018 at 15:22
  • 1
    Some of the pins on ESPs are protected against excessive voltage, personally I always err on the side of caution and use regulators and level shifters, but with the real estate restrictions I'd suggest you check the manual on what the absolute maximum is that you version of the board can take. Jan 9, 2018 at 15:24
  • Are you talking about providing power to the ESP, or just an input-pin? For power use a voltage regulator. For inputs you could indeed use a voltage divider.
    – Gerben
    Jan 9, 2018 at 16:37
  • 1
    To be clear I was talking about the power input. Jan 9, 2018 at 16:47
  • If your voltage source is high enough, spend less than a buck on a regulator like a LD1117-3.3 Jan 12, 2018 at 2:12

4 Answers 4


The datasheet usually is definitive on the allowable range of voltages.

Look in Section 5.1: Electrical Characteristics.

Working Voltage Value:

  • Min: 2.5 V
  • Typical: 3.3 V
  • Max: 3.6 V

If you have to feed in signals that could go higher than 3.3 V in normal operation, you need to either clamp it with Zener diodes, or use a voltage divider.

If you are asking about powering the chip with more than 3.3 V, don't. You can get away with a 3.3 V linear regulator and 2 capacitors so that you are powering it with no more than designed supply voltage.


The result to apply more voltage to a circuit is that the components will be burn. The same if you apply for a long time the maximum voltage. So the board works at 3.3v, your source maybe fluct between that but you will burn it if you apply 3.6 or more as a regular voltage.


Usually ESP8266 modules have an onboard voltage regulator, USB connector and a pin labeled 5V. This pin or the USB cable certainly tolerate resp. need a 5V power supply.

The ESP8266 controller itself will not survive 5V, neither at the Vcc nor at the signal pins.

BTW: a voltage divider (two resistors) is ok for signals, but does not help with the power supply.


I have 4 pieces of ESP01-S with DHT11 that connect to the WiFi every 30 minutes and send temperature data and then go into DeepSleep. In addition, an ESP01-S as a motion detector and one as a push button. These two usually in DeepSleep. All are directly connected to a Li-Ion battery as power supply. This has been running for over a year (except for changing the battery) and so far I haven't had any problems

  • 1
    Welcome to Arduino:SE. I don't think this actually answers the question. Aug 31 at 19:27
  • This is anecdotal information i.e. it might work for you but it (greatly) exceeds the manufacturer's specifications. Connecting directly to a Lithium Ion cell means the ESP8266 is exposed to voltages of over 4 V when the battery is fully charged.
    – StarCat
    Sep 1 at 9:35

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