When comparing Arduino Nano vs esp32, the Slant community recommends esp32 for most people. In the question“What are the best single-board computers?” esp32 is ranked 45th while Arduino Nano is ranked 50th. The most important reason people chose esp32 is:
Many different variants are available depending how good you are at soldering or how small it needs to be.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Same as UNO but in a small form factor
You can have almost all the features that the Arduino UNO gives you and more, while reducing the form factor and current draw.
Pro Many variants available
Many different variants are available depending how good you are at soldering or how small it needs to be.
Pro Very small
Can fit inside small devices.
Pro Very cheap
Without case can be below $5.
Pro Has ultra-low power mode
Pro Has bluetooth and wifi modules
Cons
Con Some variants require soldering
Not all variants include easily plugable pins. Usually only the more expensive variants include these.