ESP8266 Community Forum

Hi there,

I wish to ask, what is the difference between ESP-01 and ESP-01S modules (except one LED diode and the corresponding resistor)?

Thank you!

(deleted, was accidental double-posting)

The changes I've come across so far are:

ESP-01 (blue PCB) vs ESP-01S (black PCB)
- 512kB flash vs 1MB flash
- Red power LED vs -No- power LED
- Blue LED on TX vs Blue LED on GPIO2 (low = on)

Thanks for the info. Got some new ESP-01S and discovered that for my purpose, the original ESP-01 works a little bit better! Specifically, I use deep-sleep mode on these, which means I have to run a jumper from the ESP8266 chip pin 8 (GPIO16) to RST; the ESP-01S have a resistor and a cap right at the corner of the chip making it hard to get into and attach a jumper wire. Also, the ESP-01 that doesn't have a power LED means I don't need to remove the power LED . I usually do replace the 4Mbit serial flash with an 32Mbit while I'm at it...an 8Mbit is usually sufficient but the W25Q32FVSSIG are pretty cheap.