LDO for ESP32
An LDO is simple, low-noise and easy to use. It works well when input voltage is close to 3.3 V or current is moderate. The downside is heat and wasted power.
Buck converter for ESP32
A buck converter is more efficient when stepping down from 5 V, 12 V or batteries. It is often better for higher current or long battery runtime.
Which should you choose?
For low-noise simple designs, use a good LDO. For battery runtime, high current or large voltage drop, use a buck converter with good layout and low ripple.
Calculate your real values
Use the related ESP32 calculator to test your battery, regulator or brownout numbers.
Open calculator