Laser utilizes a specific wavelength of laser light which generates heat within the follicles to destroy or weaken them. Due to this it can be used on large surface area very quickly, but is only appropriate for individuals with dark hair/light skin combos.

Electrolysis technically has two different methods/tools that are used (along with a third blended technique). The most commonly used is thermolysis (short wave diathermy), which actually sends a high frequency radio wave through the probe to heat up and destroy individual follicles one by one. The other is galvanic, which sends a current into the follicle to create a chemical reaction with the pore in order to destroy it. (I’m sure you could find greater detail but that’s all I know from memory).

For me, laser felt like zapping and a lot of burning on entire sections of my face - but only lasted a few minutes total each session. However laser face was essentially sunburn that lasted a week or more, so for me laser was the worst. Thermolysis feels more like individual zaps or snaps of a rubber band (with less burning sensation in general) - it definitely hurts and I often find myself holding my breath in anticipation of the next zap. Electrolysis hasn’t burned me but instead leaves welts that last a few days. For me the worst zaps hurt less than the worst laser areas, but each of my electrolysis appts are currently an hour long… I have not experience galvanic yet, which apparently hurts the worst because each follicle takes longer. (Sorry for the book).